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Browsing Tags iPhone4S

Lens Adaptors for iPhone4S: technical details, issues and usage

August 31, 2012 · by parasam

[Note: before moving on with this post, a comment on stupid spell-checkers… my blog writer (and even Microsoft Word!) insists that “adaptor” is a mis-spelling. Not so… “adaptor” is a device that adapts one thing to another that would otherwise be incompatible, while an “adapter” is a person that adapts to new situations or environments… I’ve seen countless instances of mis-use… I fear that even educated users are deferring to software, assuming that it’s always correct. The amount of flat-out wrong instances in both spelling and grammar in most major software applications is actually scary…]

Okay, now for the good stuff…  While the iPhone (in all models) is a fantastic camera for a cellphone, it does have many limitations, some of which have been discussed in previous articles in this blog. The one we’ll address today is the fixed field-of-view (FOV) of the camera lens. Since most users are familiar with 35mm SLR (Single Lens Reflex) – or, if you are young enough to not have used film, then DSLR (Digital SLR) – and have at least an acquaintance with the relative FOV of different focal length lenses. As a quick review, the so-called “normal” lens for a 35mm sensor size is a 50mm focal length. Anything less than that is termed a “wide angle” lens, anything greater than that is termed a “telephoto” lens. This is a somewhat loose description, and at very small focal lengths (which leads to very wide angle of view) the terminology changes to a “fisheye” lens. For a more detailed explanation of focal length and other issues please see my original post on the iPhone4S camera “Basic Overview” here.

Overview

The lens that is part of the iPhone4S camera system is a fixed aperture / fixed focal length lens. The aperture is set at f2.4 while the 35mm equivalent focal length of the lens is 32mm – a moderately wide angle lens. The FOV (Field of View) for this lens is 62° [for still photos], 46° [for video]. {Note: since the video mode of 1920×1080 pixels is smaller than the sensor size used for still photos (3264×2448) the angle of view changes with the focal length held constant} The fixed FOV (i.e. not a zoom lens) affects composition of the image, as well as depth of field. A quick note: yes the iPhone (and most other cellphone cameras) have a “zoom” function, but this is a so-called “digital zoom” which is achieved by cropping and magnifying a small portion of the original image as captured on the sensor. This produces a poor quality image that has low resolution, and is avoided for any serious photography. A true zoom lens (sometimes called ‘optical zoom’) achieves this function by mechanically changing the focal length – something that is impossible to engineer for a cellphone. As a rule of thumb, the smaller the focal length, the greater the depth of field (the areas of the image that are in focus, in relation to the distance from the lens); and the greater the field of view (how much of the total scene fits into the captured image).

In order to add some variety to the compositional choices afforded by the fixed iPhone lens, the only option is to fit external adaptor lenses to the iPhone. There are several manufacturers that offer these, using a variety of mechanical devices to mount the lens. There are two basic divisions of adaptor type: those that provide external lenses and the mounting hardware; and those that provide a mechanical adaptor to use commonly available 35mm lenses with the iPhone. One example of an adaptor for 35mm lenses is here, while an example of lens+mount is here.

I personally don’t find a use for adapting 35mm lenses to the iPhone:  if I am going to deal with the bulk of a full sized lens then I will always choose to attach a real camera body and take advantage of the resolution and control that a full purpose-built camera provides. Not everyone may share this sentiment, and for those that find this useful there are several adaptors available. I do shoot a lot with the iPhone, and found that I did really want to have a relatively small and lightweight set of adaptor lenses to offer more choice in framing an image. I researched the several vendors offering such devices, and for my personal use I chose the iPro lens system manufactured by Schneider Optics. I made this choice based on two primary factors:  I had prior experience with lenses made by Schneider (their unparalleled Super Angulon wide angle for my view camera), and the precision, quality and versatility of the iPro system. This is a personal choice – ultimately any user will find what works for them – but the principles discussed here will apply to any external adaptor lens. As I have mentioned in previous posts, I am not a professional reviewer, have no relationship with any hardware or software vendor (other than the support offered as an end user), and have no commercial interest in any product I mention in this blog. I pick what I like, then write about it.

I do want to point out however, once I started using the iPro lenses and had some questions, that I received a large amount of time and assistance from the staff at Schneider Optics, particularly Niki Mustain. I would like to thank her and all the staff that so generously answered my incessant questions, and did a fair amount of additional research and testing prompted by some of my observations. They kindly made available an internal report on iPro lens performance, and the interactions with the iPhone camera (some of these issues to be discussed below). When and if they make that public (likely as an application note on their website) I will update this blog with a comment to point to that, in the meantime they have allowed me to use some of their comments on the general technology and limitations of any adaptor lens system as background for this post.

Technical specs on the iPro lens adaptor system

This particular system offers three different adaptor lenses (they can be purchased individually or as a set): Wide Angle, Telephoto and Fisheye. Here are the basic specifications:

As can be seen from the above details, the Telephoto is a 2X magnification, doubling the focal length and halving the FOV (Field of View). The Wide Angle changes the stock medium wide-angle view of the iPhone to a “very wide” wide angle (19mm equivalent – about the widest FOV provided by most variable focal length** 35mm lenses). The Fisheye offers what I would consider a ‘medium’ fisheye look, with a 12mm equivalent focal length. With fisheye lenses generally accepted as having focal lengths of 18mm or less, this falls about midway between 6mm*** and 18mm.

**There is a difference between “variable focal length” and “zoom” lenses, although most use the term interchangeably not being aware of the distinction between the two. A variable focal length lens allows a continuous change of focal length, but once the new focal length is established, the image must be refocused. A true zoom lens will maintain focus throughout the entire range of focal lengths allowed by the lens design. Obviously a true zoom lens is more difficult (and therefore costly) to manufacture. Typically, zoom lenses are larger and heavier than a variable focal length lens. It is also more difficult to create such a lens with a wide aperture (low f/stop number). To give an example, you can purchase a reasonable 70-200mm zoom lens for about $200 (with a maximum aperture of f5.6); a high quality zoom lens of the same range (70-200mm) that opens up to f2.8 will run about $2,500.

Another thing to keep in mind is that most ‘variable focal length’ lenses are not advertised as such, they are often marketed as zoom lenses, but careful testing will show that accurate focus is not maintained throughout the full range of focal lengths. Not surprising, as this is a difficult optical feat to do well, which is why high quality zoom lenses cost so much. Really good HD video or cinemaphotography zoom lenses that have an extremely wide range (often used for sports television – for example the Canon DigiSuper 80 with a zoom range of 8.8 to 710mm) can cost upwards of $163,000. Warning: playing with one of these for a few days will produce depression and optical frustration once returning to ‘normal’ inexpensive zoom lenses… A good lens is simply the most important factor in getting a great image. Period.

*** The extreme wide end of fisheye lenses is held by the Nikkor 6mm/f2.8 which is a masterpiece of engineering. With an almost insane 220° FOV, this is the widest lens for 35mm cameras of which I am aware. You won’t find this in your local camera shop however, only a few hundred were ever made – during the 1970s – 1980s. The last time one went on auction (in the UK in April 2012) it sold for just over $160,000. The objective lens is a bit over 236mm (9.25″) in diameter! Here are a few pix of this awesome lens:

actual image taken with 6mm f2.8 Nikkor fisheye

Ok, back to reality (both size and wallet-wise…)

Here are some images of my iPro lenses to give the reader a better idea of the devices which we’ll be discussing further:

The 3-lens iPro kit fully assembled for carrying/storage.

An ‘exploded view’ of all the bits that make up the 3-lens iPro system.

The Fisheye, Telephoto and Wide Angle iPro lenses.

Front view of iPro case mounted to iPhone4S, showing the attached tripod adaptor.

Rear view of the iPro case mounted on iPhone4S.

Close-up of the bayonet lens mounting feature of the iPro case.

2X Telephoto mounted on iPhone.

WideAngle lens mounted on iPhone.

Fisheye lens mounted on iPhone.

Basic use of the iPro lens system

The essential parts of the iPro lens system are the case, which allows precision alignment of the lens with the iPhone camera, and the detachable lens elements themselves. As we will discuss below, the precision and accuracy of mounting an external adaptor lens is crucial to good optical performance. It may seem trivial, but the material and case design is an important overall part of the performance of this adaptor lens system. Due to the necessary rigidity of the case material, once it is installed on the iPhone it is not the easiest to remove… I missed this important part of the instructions provided:  you must attach the tripod adaptor to the case body to provide the additional leverage needed to slightly flex the case for removal. (the hole in the rear of the case that shows the Apple logo is actually a critical design element: that is where you push with a finger of your opposite hand while flexing the case in order to pop out the phone from the case).

In addition to providing the necessary means for taking the iPhone out of the case if you should need to (and you really won’t: I found that this case works just fine as an everyday shell for the phone, protecting the edges, insulating the metallic sideband to avoid the infamous ‘hand soaking up microwaves dropped call iPhone effect’, and is slim enough that it fits perfectly in my belt-mounted carrying case), the tripod mounting screw provides a very important improvement for iPhonography: stability. Even if you don’t use any of the adaptor lenses, the ability to affix the phone to a tripod (or even a small mono-pod) is a boon to getting better photographs with the iPhone. Rather than bore you with various laws of physics and optic science, just know that the smaller the sensor, the more a resultant image is affected by camera movement. The simple truth is that the very small sensor size of the iPhone camera, coupled with the light weight and small case size of the phone, means that most users unconsciously jiggle the camera a lot when taking an image. This is the single greatest reason for lack of sharpness in iPhone images. To compound things, the smaller the sensor size, the less sensitive it is for gathering light, which means that often, in virtually anything but direct sunlight, the iPhone is shooting at relatively slow shutter speeds, which only exaggerates camera movement.

Since the EXIF data (camera image metadata) is collected with each shot, you can see afterwards what shutter speed was used by the iPhone on each of your shots. The range of shutter speeds on the iPhone4S is from 1/15 sec to 1/2000 sec. Any shutter speed slower than 1/250 sec will show some blurring if the camera moves at all during the shot. So, whenever possible, brace your phone against a rigid object when shooting, particularly in partial shade or darker surroundings. Since often a suitable fence post, lamp pole or other object is not right where you need it for your shot, the ability to use some form of tripod will often provide a superior result for your image.

The adaptor lenses themselves twist into the case with a simple bayonet mount. As usual with any fine optics, take care to avoid dropping, scratching or otherwise damaging the delicate optical surfaces of the lenses. The telephoto lens will most benefit from tripod use (when possible), as the narrower the angle of view, the more pronounced camera shake is on the image. On the other hand, the fisheye lens can be handheld for most work with no visible impairment. A note on use of the fisheye lens:  the FOV is so wide that it’s easy for your hand to end up in the image… take some care and practice with how you hold the phone when using this lens.

Optical issues with adaptor lenses, including the iPro lens system

After using the adaptor lenses for a short time, I found several impairments in the images taken. Essentially the artifacts result in a lack of sharpness towards the edge of the image, and color fringing of certain objects near the edge of the frame. I went on to perform extensive tests of each of the lenses and then forwarded my concerns to the staff at Schneider Optics. To my pleasure, they were open to my concerns, and performed a number of tests in their own lab as well. While I will discuss the details below, the bottom line is that both myself and the iPro team agrees that external adaptor lenses are not a perfect science, particularly with the iPhone. We must remember, for all the fantastic capabilities that this device exhibits… it’s a bloody cellphone! I have every confidence that Schneider (and probably other vendors as well) have made every effort within the scope of practicality and budget for such lenses to minimize the side-effects. I have found the actual optical precision of the iPro lenses (as measured for such things as MTF [Modulation Transfer Function – an objective measurement of the resolving capability of a lens system], illumination fall-off, chromatic and geometric aberrations, optical alignment and contrast ratio) are excellent – particularly for lenses that are really quite inexpensive compared to their quality.

The real issue lies with the iPhone camera system itself: Apple never designed this camera to interoperate with external adaptor lenses. One cannot fault the original manufacturer for attempting to produce a piece of hardware that offers good performance at a reasonable price within a self-contained system. The iPhone designers have treated the totality of the hardware and software of the camera system as a fixed and closed universe. This is typical of the way that Apple designs both their hardware and software. There are both pros and cons to this philosophy:  the strong advantage is the ability to blend design characteristics of both hardware and software to mutually complement each other in the effort to meet design criteria with a time/cost budget; the disadvantage is the lack of easy adaptability in many cases for external hardware or software to easily interoperate with Apple products. For example, the software development guidelines for Apple devices are the most stringent in the entire industry. You work within the framework provided, or you don’t get approval for your app. Every app intended for any iDevice must be submitted to Apple directly for testing and approval. This is virtually unique in the entire computer/cellphone industry. (I’m obviously not talking about the gray area of ‘jailbroken’ phones and software).

The way in which this design philosophy shows up in relation to external adaptor lenses is this: the iPhone camera is an amazingly good camera for it’s size, cost and weight, but it was never designed to be complementary to external lenses. Certain design choices that are not evident when images are taken with the native camera show up, sometimes rather glaringly, when external lenses are coupled with the iPhone camera. One might say that latent issues in the lens and sensor design are significantly amplified by external adaptor lenses. This issue is endemic to any external lens, not just the iPro lenses I am discussing here. Each one will of course have its own unique ‘fingerprint’ of interaction with the iPhone camera, but the general issues discussed will be the same.

As usual, I bring all this up to share with my readers the best information I can find or develop in the pursuit of what’s realistically possible with this great little camera. The better we know the capabilities and limitations of our tools, the better able we are to make the images we want. I have taken some great shots with these adaptor lenses that would have been impossible to create any other way. I can live with the distortions introduced as a compromise to get the kind of shot that I want. The more aware I am of what the issues are, the better I can attempt (while composing a shot) to attempt to minimize the visibility of some of these artifacts.

To get started, here are some example shots:

[Note:  all shots are unretouched from the iPhone camera, the only adjustment is resizing to fit the constraints of this blog format]

iPhone4 Normal (no adaptor lens)

iPhone4 WideAngle adaptor lens

iPhone4 Fisheye adaptor lens

iPhone4 Telephoto adaptor lens

iPhone4S #1 Normal

iPhone4S #1 WideAngle

iPhone4S #1 Fisheye

iPhone4S #1 Telephoto

iPhone4S #2 Normal

iPhone4S #2 WideAngle

iPhone4S #2 Fisheye

iPhone4S #2 Telephoto

The above shots were taken to test one of the first potential causes for the artifacts in the images: the softening towards the edges as well as the color fringing of bright areas near the edge of the image (chromatic aberration). A big potential issue with externally mounted adaptor lenses for the iPhone is lens alignment. The iPhone lens is physically aligned to the sensor as part of the entire camera assembly. This unitary assembly is then inserted into the case during final manufacture of the device. Since Apple never considered the use of external adaptor lenses, no effort was made to ensure perfect alignment of the camera assembly into the case. As can be seen from my blog on the iPhone hardware (showing detailed images of an iPhone torn apart), the camera assembly is simply pressed into place – there is no precision mechanical lock to align the optical axis of the camera with the case. In addition, the actual camera lens is protected by being installed behind a clear plastic window that is part of the outer case itself.

What this means is that if the camera assembly is tilted even very slightly it will produce a “tilt-shift” de-focus effect when coupled with an external lens:  the center of the image will be in focus, but both edges will be out of focus. One side will actually be focused a bit behind the sensor plane, the other side will be focused a bit in front of the sensor plane.

The above diagram represents an extreme example, but you can see that if the lens is tilted in relation to the image sensor plane, the plane of focus changes. Objects at the edge of the frame will no longer be in focus, while objects in the center of the frame will remain in focus.

In order to eliminate this probability from my tests, I used three separate iPhones (one iPhone4 and two iPhone4S models). While not a large sample statistically, it did provide some certainty that the issues I was observing were not related to a single iPhone. You can see from the examples above that all of the adaptor lens shots exhibit some degree of the two artifacts (defocused edges and chromatic aberration). So further investigation was required in order to attempt to understand the root cause of these distortions.

Since the first set of test shots was not overly ‘scientific’ (back yard), I was advised by the staff at Schneider that a brick wall was a good test subject. It was easy to visualize the truth of this, so I went off in search of a large public test chart (brick wall…)

WideAngle taken from 15 ft.

Fisheye taken from 15 ft.

Telephoto taken from 15 ft.

To add some control to the shots, and reduce potential errors of camera movement that may affect sharpness in the image, the above and all subsequent test shots were taken while the iPhone was mounted on a stable tripod. In addition, each shot was taken from exactly the same camera position (in the above shots, 15 feet from the wall). Two things stood out here: 1) there was a lack of visible chromatic aberration [I think likely due to the flat lighting on the wall and lack of high contrast edges, which typically enhance that form of artifact]; and 2) the soft focus artifact is more pronounced on the left and right sides as opposed to the top and bottom edges. [More on why I think this may occur later in this article].

WideAngle, 8 ft.

Fisheye, 8 ft.

WideAngle, 30 ft.

Fisheye, 30 ft.

Telephoto, 30 ft.

WideAngle, 50 ft.

Fisheye, 50 ft.

Telephoto, 150 ft.

Telephoto, 150 ft.

Telephoto, 500 ft.

The above set of images represented the next test series of shots. Here, various distances to the “test chart” [this time I needed even a larger ‘chart’ so had to find a 3-story brick building…] were used in order to see what effect that may have on the resultant image. A few ‘real world’ images were shot using just the telephoto at long distances – here the large distance from camera to subject, using a telephoto lens, would normally result in a completely ‘flat’ image with everything in the same focal plane. Once again, we continue to see soft focus and chromatic aberrations at the edges.

Normal (no adaptor), auto-focus

Normal, Selective Focus

WideAngle, Auto Focus

WideAngle, Selective Focus

Fisheye, Auto Focus

Fisheye, Selective Focus

Telephoto, Auto Focus

Telephoto, Selective Focus

This last set of test shots was suggested by the Schneider staff, based on some tests they ran and subsequent discussions. One theory is that there is a difference in how the iPhone camera internal software (firmware + OS kernel software – not anything a camera app developer has access to) handles auto-focus vs selective-focus. Selective focus is where the user can select the focus area, usually with a little square that can be moved to different parts of the image. In all the above tests, the selective focus area was set to the center of the image. In theory, since my test images were flat and all at the same difference from the camera, there should have been no difference between auto-focus or selective-focus, no matter which lens was used. Careful examination of the above images shows an inconsistent result:  the fisheye showed no difference between the two focus modes, the normal and telephoto looked better with selective focus, while the wideangle looked best when auto focus was applied.

The internal test report I received from Schneider pointed out another potential anomaly, one I have not yet had time to attempt to reproduce: using selective focus off-center in the image. This usage appeared to generate results that would be unexpected in normal photographic work: the area of selective focus was sharp, most of the rest of the image was a bit softer, but a mirror image position of the original selective focus region was once again sharp on the opposite side of the image. This does seem to clearly point to some image-enhancement algorithms behaving in an unexpected fashion.

The issue of auto-focus methods is a bit beyond the scope of this article, but some considerable research shows that the most likely methodology used in the iPhone camera is passive detection (that is certain – there is no range finder on an iPhone!) controlled lens barrel or lens element adjustment. There are a large number of vendors that support this form of auto-focus (and here, I mean ‘not manual focus’ since there is no mechanical focus ring on cellphones… – the ‘auto-focus’ can either be entirely automatic [as I use the term “auto-focus” in my tests above] or selective area auto-focus, where the user indicates a region of the image on which the auto-focus is concentrated. One of the most advanced methods is MEMS (Micro-Electrical Mechanical Systems) which moves a single optical element within the lens barrel, another popular method is the ‘voice-coil’ micro-motor which moves the entire lens barrel to effect focus.

With the advances brought to bear with iOS5, including face area recognition (the camera attempts to recognize faces in the image and focus on those when in full auto-focus mode), it is apparent that significant image recognition and processing are being done at the kernel level, before any camera app ‘gets their hands on’ the camera controls. The bottom line is that there may well be some interactions between the way in which the passive detection and image processing algorithms are affected by an unexpected (to the iPhone software) presence of an external adaptor lens. Another way to put this is that the internal software of the camera is likely ‘tuned’ to the lens that is part of the camera assembly, and the addition of a significant change to the optical pattern drawn on the camera sensor (now that a telephoto lens adaptor is attached) alters the focusing algorithm in an unexpected manner, producing the artifacts we see in the examples.

This issue is not at all unknown in engineering and quality control: a holistically designed system where all of the variables are thought to be known can be significantly degraded when even one element is externally modified without knowledge of the full scope of design parameters. This often occurs with after-market additions or changes to automobiles. One simple example is if you change the tire size (radius, not width) the speedometer is no longer is accurate – the entire system of the car, including wheel and tire diameter, was part of the calculus for determining how many turns of the axle per minute (all the speedometer mechanism actually measures) are required to indicate X amount of kph (or mph) on the instrument panel.

Another factor that may have a material effect on the focus and observed chromatic aberration is the lens design itself, and how an external adaptor lens may interact with the native design. Simple lenses are often portions of a sphere, so called “spherical lenses.”  Such a lens suffers from significant optical aberrations, as not all of the light rays that are focused by a spherical lens converge to a single point (producing a lack of sharp focus). Also, such lenses bend different colors of light differently, leading to chromatic aberrations (where one sees color fringing, usually blue/purple on one side of a high contrast object and green/yellow on the opposite side). Most high quality modern camera lenses are either aspherical (specially modified shapes that deviate away from a perfect spheroid shape) or groups of elements, some of which may be spherical and others aspherical. Several examples are shown below:

We know from published literature that the lens used in the iPhone4S is a 5 element lens system with at least several aspherical elements. A diagram released by Apple is shown below:

iPhone4 lens system [top] and iPhone4S lens system [bottom]

Again, as described earlier, the iPhone camera system was designed as a unitary system, with factors from the lens system, the individual lens elements, the sensor, firmware and kernel software all becoming known variables in a highly complex opto-electronic equation. The introduction of an external adaptor array of additional elements can produce unplanned effects. All in all, the various vendors of such adaptor lenses, including iPro, have done a good job in dealing with many unknowns. Apple is a highly secretive manufacturer, and does not publish much information. Attempts to gain further technical knowledge are very difficult, at some point one invariably comes up against Apple’s draconian NDAs (Non-Disclosure Agreements) which have penalties large enough to deter even the most aggressive seekers of information. Even the accumulation of knowledge that I have acquired over the past year while writing about the iPhone has been slow, tedious and has taken a tremendous amount of research and ‘fact comparison.’

As a final example, using a more real-world subject, here are a few camera images and screen shots that demonstrate the challenge if one attempts to correct, using post-production techniques, some of the errors introduced by such a lens adaptor:

Original image, unretouched but annotated.

The original image shows significant chromatic aberrations (color fringing) around the reflections in the shop window, grout lines in the brickwork on the pavement, and on the left side of the man’s shirt.

Editing using Photoshop ‘CameraRaw’ to attempt to correct the chromatic aberrations.

Using the Photoshop Camera Raw module, it is possible to manually correct for color fringing shifts… but this affects the entire image. So a fix for the edges causes a new set of errors in the middle of the image.

Chromatic aberrations removed from around the reflections in the window…

Notice here that the color fringing is gone from around the bright reflections in the window, but now the left edge of the man’s shirt has the color shifted, leaving only the monochromatic outline behind, producing a dark gray edge instead of the uniform blue that should exist.

…but reciprocal chromatic edge errors are introduced in the central portion of the image where highly saturated colors abut more neutral areas.

Likewise, the green paint on the steel column has shifted, revealing a gray line on the right of the woman’s leg, with a corresponding shift of the flesh tone onto the green steelwork on the left side of her leg.

final retouched shot after ‘painting in’ was performed to resolve the chroma offset errors in the central portion of the image.

To fix all these new errors, a technique known as ‘painting in’ was used, sampling and filling the color errors with the correct shade, texture and intensity. This takes time, skill and patience. It is impractical in the most part – this was done as an example.

Summary

The use of external adaptor lenses, including the iPro system discussed here, can offer a useful extension to the creative composition of images with the iPhone. Such lenses bring a set of compromises with them, but hopefully once these are known, careful choice of lighting, camera position and other factors can be used to reduce the visibility of such effects. As with any ‘creative device’ less is often more… sparing use of such adaptors will likely bring the best results. However, there are shots that I have obtained with the iPro that would have been impossible with the basic iPhone camera/lens, so I happy to have this additional tool.

To close, here are a few more examples using the iPro lenses:

Fisheye

WideAngle

Telephoto

iPhone4S – Section 4c: Camera Plus Pro app

April 13, 2012 · by parasam

This is a similar app to Camera+ (but not made by the same developers). (This version costs $1.99 at the time of this post – $1 more than Camera+). It’s similar in design and function. The biggest differences are:

  • Ability to tag photos
  • More setup options on selections (self-timer, burst mode, resolution, time lapse, etc.)
  • More sharing options
  • Ability to add date and copyright text to photo
  • A ‘Quick Roll’ (light table type function) has 4 ‘bins’ (All, Photos, Video, Private – can be password protected)
  • Can share photos via WiFi or FTP
  • Bing search from within app
  • Separate ‘Digital Flash’ filter with 3 intensity settings
  • Variable ‘pro’ adjustments in edit mode (Brightness, Saturation, Hue, Contrast, Sharpness, Tint, Color Temperature)
  • Different filters than Camera+, including special ‘geometric distortion’ filters
  • Quick Roll design for selecting which photos to Edit, Share, Sync, Tag, etc.
  • Still Camera Functions  [NOTE: the Video Camera functions will be discussed separately in later in this series when I compare video apps for the iPhone]
    • Ability to split Focus area from Exposure area
    • Can lock White Balance
    • Flash: Off/On (for the 4 & 4S); this feature changes to “Soft Flash” for iPhone 3GS and Touch 4G.
    • Front or Rear camera selection
    • Digital Zoom
    • 4 Shooting Modes: Normal/Stabilized/Self-Timer/Burst (part of the below Photo Options menu)
    • Photo options:
      • Sound On/Off
      • Zoom On/Off
      • Grid Lines On/Off
      • Geo Tags On/Off
      • SubMenu:
        • Tags:  select and add tags from list to the shot; or add a new tag
        • Settings:  a number of advanced settings for the app
          • Photos:
            • Timer (select the time delay for self-timer: 2-10 seconds in 1 second increments
            • Burst Mode (select the number of pictures taken when in burst mode: 3-10
            • Resolution (Original [3264×2448]; Medium [1632×1224]; Low [816×612]) – NOTE: these resolutions for the iPhone4S, each different hardware model supported by this app has a different set of resolutions set by the sensor. Essentially it is Full, Half and Quarter resolution. The exact numbers for each model are in the manual.
            • Copyright (sets the copyright text and text color)  [note: this is a preset – the actual ‘burn in’ of the copyright notice into the image is controlled during Editing]
            • Date (toggle date display on/off; set date format; text color)
        • Videos (covered in later section)
        • Private Access Restriction (Set or Change password for the Private bin inside the Quick Roll)
        • Tags (edit, delete, add tag names here)
        • Share (setup and credentials for social sharing services are entered here):
          • Facebook
          • Twitter
          • Flickr
          • Picasa
          • YouTube (for videos)
        • Review (a link to review the app)
      • Info:
        • Some ‘adware’ is here for other apps from this vendor, and a list of FAQs, Tips, Tricks (all of which are also in the manual available for download as a pdf from here)
  • Live Filters:
    • A set of 18 filters that can be applied before taking your shot, as opposed to adding a filter after the shot during Editing.
      • BW
      • Vintage
      • Antique
      • Retro
      • Nostalgia
      • Old
      • Holga
      • Polaroid
      • Hipster
      • XPro
      • Lomo
      • Crimson
      • Sienna
      • Emerald
      • Bourbon
      • Washed
      • Arctic
      • Warm
    • A note on image quality using Live Filters. A bit more about the filters will be discussed below when we dive into the filter details, but some test shots using various Live Filters show a few interesting things:
      • The pixel resolution stays the same whether the filter is on or off (3264×2448 in the case of the iPhone4S).
      • While the Live Filter function is fully active during preview of an image, once you take the shot there is a delay of about 3 seconds while the filtering is actually applied to the image. Some moving icons on the screen notify the user. Remember that the screen is 960×640 while the full image is 3264×2448 (13 X larger!) so it takes a few seconds to filter all those additional pixels.
      • This does mean that when using Live Filter you can’t use Burst Mode (it is turned off when you turn on a Live Filter), and you can’t shoot that rapidly.
      • Although the pixel dimensions are unchanged, the size of the image file is noticeably smaller when using Live Filters than when not. This can only mean that the jpeg compression ratio is higher (same amount of input data; smaller output data; compression ratio mathematically must be higher).
      • I first noticed this when I went to email myself a full resolution image from my phone to my laptop [faster for one or two pix than syncing with iTunes] as I’m researching for this blog – the images were on average 1.7MB instead of the 2.7MB average for normal iPhone shots.
      • I tested against four other camera apps, including the native Camera app from Apple, and all of them delivered images averaging 2.7MB per image.
      • I then tested this app (Camera Plus Pro) in Unfiltered mode, and the size of the output file jumps up to an average of 2.3MB per image. Not as high as most of the others, but 35% larger. Therefore a 35% reduction in compression ratio. I’ll run some more objective tests during the filter analysis section below, but both in file size and visual observation, the images appear more highly compressed.
      • This does not mean that a more compressed picture is inferior, or softer, etc. – it is highly dependent on subject material, lighting, etc. But, what is true is that a more highly compressed picture will tend to show artifacts more easily in difficult parts of the frame than will the same image at a lower compression ratio.
      • Just all part of my “Know Your Tools” motto…
      • Edit Functions
        • Crop
          • Freeform (variable aspect ratio)
          • Square (1:1 aspect ratio)
          • Rectangular (2:3 aspect ratio) [portrait]
          • Rectangular (3:2 aspect ratio) [landscape]
          • Rectangular (4:3 aspect ratio) [landscape]
  • Rotation
    • Flip Horizontal
    • Right
    • Left
    • Flip Vertical
  • Digital Flash [a filter that simulates flash illumination]
    • Small
    • Medium
    • Large
  • Adjust [image parameter adjustments]
    • Brightness
    • Saturation
    • Hue
    • Contrast
    • Sharpness
    • Tint
    • Color Temperature
  • Effects
    • Nostalgia – 9 ‘retro’ effects
      • Coffee
      • Retro Red
      • Vintage
      • Nostalgia
      • Retro
      • Retro Green
      • 70s
      • Antique
      • Washed
    • Special – 9 custom effects
      • XPro
      • Pop
      • Lomo
      • Holga
      • Diana
      • Polariod
      • Rust
      • Glamorize
      • Hipster
    • Color – 9 tints
      • Black & White
      • Sepia
      • Sunset
      • Moss
      • Lucifer
      • Faded
      • Warm
      • Arctic
      • Allure
    • Artistic – 9 special filters
      • HDR
      • Fantasy
      • Vignette
      • Grunge
      • Pop Art
      • GrayScale
      • Emboss
      • Xray
      • Heat Signature
    • Distortion – 9 geometric distortion (warping) filters
      • Center Offset
      • Pixelate
      • Bulge
      • Squeeze
      • Swirl
      • Noise
      • Light Tunnel
      • Fish Eye
      • Mirror
  • Borders
    • Original (no border)
    • 9 border styles
      • Thin White
      • Rounded Black
      • Double Frame
      • White Frame
      • Polaroid
      • Stamp
      • Torn
      • Striped
      • Grainy

Camera Functions

[Note:  Since this app has a manual available for download that does a pretty fair job of describing the features and how to access and use them, I will not repeat that information here. I will discuss and comment on the features where I believe this will add value to my audience. You may want to have a copy of the manual available for clarity while reading this blog.]

The basic use and function of the camera is addressed in the manual, what I will discuss here are the Live Filters. I have run a series of tests to attempt to illustrate the use of the filters, and provide some basic analysis of each filter to help the user understand how the image will be affected by the filter choice. The resolution of the image is not reduced by the use of a Live Filter – in my case (testing with iPhone4S) the resultant images are still 3264×2448 – native resolution. There are of course the effects of the filter, which in some cases can reduce apparent sharpness, etc.

A note on my testing procedure:  In order to present a uniform set of comparison images to the reader, and have them be similar to my standard test images, the following steps were taken:

Firstly:  my standard test images that I use to analyze filters/scenes/etc for any iPhone camera app consists of two initial test images:  a technical image (calibrated color and grayscale image), and a ‘real-world’ image – a photo I shot of a woman in the foreground with a slightly out-of-focus background. The shot has a wide range of lighting, color, a large amount of skin tone for judging how a given filter changes that important parameter, and a fairly wide exposure range.

 The original source for the calibration chart was a precision 35mm slide (Kodak Q60, Ektachrome) that was scanned on a Nikon Super Coolscan 5000ED using Silverfast custom scanner software. The original image was scanned at 4000dpi, yielding a 21megapixel image sampled at 16bits per pixel. This image was subsequently reduced in gamut (from ProPhotoRGB to sRGB) and size (to match the native iPhone4S resolution of 3264×2448) and bit depth (8bits per pixel) . The image processing was performed using Photoshop CS5.5 in a fully color-calibrated workflow.

The source for the ‘real-world’ image was initially captured using a Nikon D5000 DSLR fitted with a Nikkor 200mm F2.8 prime lens (providing an equivalent focal length of 300mm compared to full-frame 35mm – the D5000 is a 2/3 size sensor [4288×2848]). The exposure was 1/250 sec @ f5.6 using camera raw format – no compression. That camera body captures in sRGB color space, and although outputs a 16bit per pixel format, the sensor is really not capable of anything more than 12 bits in a practical sense. The image was processed in Photoshop CS5.5 in a similar manner as above to yield a working image of 3264×2448, 8 bits per pixel, sRGB.

These image pairs are what are used throughout my blog for analyzing filters, by importing into each camera app as a file.

For this test of Live Filters, I needed to actually shoot with the iPhone, since there is no way using this app to apply the Live Filters to a pre-existing image. To replicate the images discussed above as closely as possible, the following procedure was used:

For the calibration chart, the same source image was used (Kodak Q60), this time as a precision print in 4″x5″ size. These prints were manufactured by Kodak under rigidly controlled processes and yield a highly accurate reflective target. (Most unfortunately, with the demise of Kodak, and film/print processing in general, these are no longer available. Even with the best of storage techniques, prints will fade and become inaccurate for calibration. It will be a challenge to replace these…)  I used my iPhone4S to make the exposures under controlled lighting (special purpose full-spectrum lighting set to 5000°K).

For the ‘real-world’ image, I wanted to stay with the same image of the woman for uniformity, and it provides a good range of test values. To accomplish that (and be able to take the pictures with the iPhone) was challenging, since the original shot was impossible to duplicate in real life. I started with the same original high resolution image (in Photoshop) in its original 16bit, high-gamut format. I then printed that image using a Canon fine art inkjet printer (Pixma Pro 9500 MkII), using a 16 bit driver, on to high quality glossy photo paper at a paper size of 13″ x 19″. At a print density of 267dpi, this yielded an image of over 17megapixels when printed. The purpose was to ensure that no subsampling of printed pixels would occur when photographed by the 8megapixel sensor in the iPhone. [Nyquist sampling theory demands a minimum of 2x sampling – 16megapixels in this case – to ensure that). I photographed the image with the same controlled lighting as used above for the calibration chart. I made one adjustment to each image for normalization purposes:  I mapped the highest white level in the photograph (the clipped area on the subject’s right shoulder – which was pure white in the original raw image) to just reach pure white in the iPhone image. This matched the tonal range for each shot, and made up for the fact that even with a lot of light in the studio it wasn’t enough to fully saturate the little tiny iPhone sensor. No other adjustments of any kind were made. [This adjustment was carried out by exporting the original iPhone image to Photoshop to map the levels].

While even further steps could have been taken to make the process more scientifically accurate, the purpose here is one of relative comparison, not absolute measurement, so I feel the steps taken are sufficient for this exercise.

The Live Filters:

Live Filter = BW

Live Filter = BW

The BW filter provides a monochrome adaptation of the original scene. It is a high contrast filter, this can clearly be seen in the test chart, where columns 1-3 are solid black, as well as all grayscale chips from 19-22. Likewise, on the highlight end of the scale, chips 1-3 have no differentiation. The live image shows this as well, with a strong contrast throughout the scene.

Live Filter = Vintage

Live Filter = Vintage

The Vintage filter is a warming filter that adds a reddish-brown cast to the image. It increases the contrast some (not nearly as much as the previous BW filter) – this can be seen in the chart in the area of columns 1-2 and rows A-J. The white and black ends of the grayscale are likewise compressed. Any cool pastel colors either turn white or a pale warm shade (look at columns 9-11). The live image shows these effects, note particularly how the man’s blue shirt and shorts change color remarkably. The increase in contrast, couple with the warming tint, does tend to make skin tones blotchy – note the subject’s face and chest.

Live Filter = Antique

Live Filter = Antique

The Antique filter offers a large amount of desaturation, a cooling of what color remains, and an increase in contrast. Basically, only pinks and navy blues remain in the color spectrum, and the chart shows the clipping of blacks and whites. The live image shows very little saturation, only some dark blue remains, with a faint pink tinge on what was originally the yellow sign in the window.

Live Filter = Retro

Live Filter = Retro

The Retro filter attempts to recreate the look of cheap film cameras of the 1960’s and 1970’s. These low quality cameras often had simple plastic lenses, light leaks due to imperfect fit of components, etc. The noticeable chromatic aberrations of the lens and other optical ‘faults’ have now seen a resurgence as a style, and that is emulated with digital filters in this and others shown below. This particular filter shows a general warming, but with a pronounced red shift in the low lights. This is easily observable in the gray scale strip on the chart.

Live Filter = Nostalgia

Live Filter = Nostalgia

Nostalgia offers another variation on early low-cost film camera ‘look and feel’. As opposed to the strong red shift in the lowlights of Retro, this filter shifts the low-lights to blue. There is also an increase in saturation of both red and blue, notice that in the chart. The green column, #18, hardly has any change in saturation from the original, while the reds and blues show noticeable increases, particularly in the low-lights. The highlights have a general warming trend, showed in the area bounded by columns 13-19 and rows A-C. The live shot shows the strong magenta/red shift that this filter caused on skin tones.

Live Filter = Old

Live Filter = Old

The Old filter applies significant shifts to the tonal range. It’s not exactly a high contrast filter, although that result is apparent in the ratio of the highlight brightness to the rest of the picture. There is strong overall reduction in brightness – in the chart all differentiation is lost below chip #16. There is also desaturation, this is more obvious when studying the chart. The highlights, like many of these filter types, are warmed toward the yellow spectrum.

Live Filter = Holga

Live Filter = Holga

The Holga filter is named after the all-plastic camera of the same name – from Hong Kong in 1982. A 120 format roll-film camera, the name comes from the phrase “ho gwong” – meaning ‘very bright’. The marketing people twisted that phrase into HOLGA. The actual variations show a warming in the highlights and cooling (blue) in the lowlights. The contrast is also increased. In addition, as with many of the Camera Plus Pro filters, there is a spatial element as well as the traditional tonal and chromatic shifts:  in this case a strong red tint in one corner of the frame. My tests appear to indicate that the placement of this (which corner) is randomized, but the actual shape of the red tint overlay is relatively consistent. Notice that in the chart the overlay is in the upper right corner, in the live shot it moved to lower right. There is also desaturation, this is noticeable in her skin, as well as the central columns of the chart.

Live Filter = Polaroid

Live Filter = Polaroid

The Polaroid filter mimics the look of one of the first ‘instant gratification’ cameras – the forerunner of digital instant photography. The PLC look (Polariod Land Camera) was contrasty with crushed blacks, tended towards blue in the shadows, and had slightly yellowish highlights. This particular filter has a pronounced magenta shift in the skin tones that is not readily apparent from the chart – one of the reasons I always use these two different types of test images.

Live Filter = Hipster

Live Filter = Hipster

The Hipster filter effect is another of the digital memorials to the original Hipstamatic camera – a cheap all plastic 35mm camera that shot square photos. Copied from an original low-cost Russian camera, the two brothers that invented it only produced 157 units. The camera cost $8.25 in 1982 when it was introduced. With a hand-molded plastic lens, this camera was another of the “Lo-Fi” group of older analog film cameras whose ‘look’ has once again become popular. The CameraPlusPro version shows pronounced red in the midtones, crushed blacks (see column 1-2 in the chart and chips #18 and below), along with increased contrast and saturation. In my personal view, this look is harsher and darker than the actual Hipstmatic film look, which tended towards raised blacks (a common trait of cheap film cameras, the backs always leaked a bit of light so a low level ‘fog’ of the film base always tended to raise deep blacks [areas of no light exposure in a negative] to a dull gray); a softer look (lower contrast due to raised blacks) and brighter highlights. But that’s purely a personal observation, the naming of filters is arbitrary at best, that’s why I like to ‘look under the hood’ with these detailed comparisons.

Live Filter = XPro

Live Filter = XPro

The XPro filter as manifested by the CameraPlusPro team looks very similar to their Nostalgia version, but the XPro has highlights that are more white than the yellow of Nostalgia. The term XPro comes from ‘cross-process’ – what happens when you process film in the wrong developer, for instance developing E-6 transparency film in C-41 color negative chemistry. The effects of this process are highly random, although there is a general tendency towards high contrast, unnatural colors, and staining. In this instance, the whites are crushed a bit, blacks tend blue, and contrast is raised.

Live Filter = Lomo

Live Filter = Lomo

The Lomo filter effect is designed to mimic some of the style of photograph produced by the original LOMO Plc camera company of Russia (Leningrad Optical Mechanical Amalgamation). This was a low cost automatic 35mm film camera. While still in production today, this and similar cameras account for only a fraction of LOMO’s production – the bulk is military and medical optical systems – and are world class… Due to the low cost of components and production methods, the LOMO camera exhibited frequent optical defects in imaging, color tints, light leaks, and other artifacts. While anathema to professional photographers, a large community that appreciates the quirky effects of this (and other so-called “Lo-Fi” or Low Fidelity) cameras has sprung up with a world-wide following. Hence the Lomo filter…

This particular instance shows increased contrast and saturation, warming in the highlights, green midtones, and like some other CameraPlusPro filters, an added spatial effect (the red streak – again randomized in location, it shows in upper left in the chart, lower right in the live shot). [Pardon the pilot error:  the soft focus of the live shot was due to faulty autofocus on that iPhone shot – but I didn’t notice it until comping the comparison shots several days later, and didn’t have the time to reset the environment and reshoot for one shot. I think the important issues can be resolved in spite of that, but did not want my readers to assume that soft focus was part of the filter!]

Live Filter = Crimson

Live Filter = Crimson

The Crimson filter is, well, crimson! A bit overstated for my taste, but if you need a filter to make your viewers think of “The Shining” then this one’s for you! What more can I say. Red. Lots of it.

Live Filter = Sienna

Live Filter = Sienna

The Sienna filter always makes me think of my early art school days, when my well-meaning parents thought I needed to be exposed to painting… (burnt sienna is a well-know oil pigment, an iron oxide derivative that is reddish-brown. My art instructor said “think tree trunks”.)   Alas, it didn’t take me (or my instructor) long to learn that painting with oils and brushes was not going to happen in this lifetime. Fortunately I discovered painting with light shortly after that, and I’ve been in love with the camera ever since. The Sienna as shown here is colder than the pigment, a somewhat austere brown. The brown tint is more evident in the lowlights, the whites warm up just slightly. As in many of the CameraPlusPro filters, the blacks are crushed, which creates an overall look of higher contrast, even if the midtone and highlight contrast levels are unchanged (look at the grayscale in the chart). There is also an overall desaturation.

Live Filter = Emerald

Live Filter = Emerald

Emerald brings us, well, green… along with what should now be familiar:  crushed blacks, increased contrast, desaturation.

Live Filter = Bourbon

Live Filter = Bourbon

The Bourbon filter resembles the Sienna filter, but has a decidedly magenta cast in the shadows, while the upper midtones are yellowish. The lowered saturation is another common trait of the CameraPlusPro filters.

Live Filter = Washed

Live Filter = Washed

The Washed filter actually looks more like ‘unwashed’ print paper to me.. Let me explain:  before the world of digits descended on photography, during the print process (well, this applies to film as well but the effect is much better known in the printing process), after developing, stopping and fixing, you need to wash the prints. Really, really well. For a long time, like 30-45 minutes under flowing water. This is necessary to wash out almost all of the residual thiosulfate fixing chemical – if you don’t, your prints will age prematurely, showing bleaching and staining, due to the slow annihilation of elemental silver in the emulsion by the remaining thiosulfate. The prints will end up yellowed and a bit faded, in an uneven manner. In this digital approximation, the biggest difference is (as usual for this filter set) the crushed blacks. In the chemical world, just the opposite would occur, as the blacks in a photographic print have the highest accumulation of silver crystals (that block light or cover up the white paper underneath). The other attributes of this particular filter are: strongly yellowed highlights, lowlights tend to blue, increased contrast and raised saturation.

Live Filter = Arctic

Live Filter = Arctic

This Arctic filter looks cold! Unlike the true arctic landscape (which is subtle but has an amazing spectrum of colors), this filter is actually a tinted monochrome. The image is first reduced to black and white, then tinted with a cold blue. This is very clear by looking at the chart. It’s an effect.

LIve Filter = Warm

Live Filter = Warm

After looking so cold in the last shot, our subject is better when Warm. Slightly increased saturation and a yellow-brown cast to the entire tonal range are the basic components of this filter.

Edit Functions

This app has 6 groups of edit functions:  Crop, Rotate, Flash, Adjust, Filters and Borders. The first two are self-evident, and are more than adequately explained in the manual. The “how-to” of the remaining functions I will leave to the manual, what will be discussed here are examples of each variable in the remaining four groups.

Flash – also known as “Digital Flash” – a filter designed to brighten an overly dark scene. Essentially, this filter attempts to bring the image levels up to what they might have been if a flash had been used to take the photograph initially. As always, this will be a ‘best effort’ – nothing can take the place of a correct exposure in the first place. The most frequent ‘side effects’ of this type of filter are increased noise in the image (since the image was dark in the first place – and therefore would have substantial noise due to the nature of CCD/CMOS sensors), raising the brightness level will also raise the appearance of the noise; and white clipping of those areas of the picture that did receive normal, or near-normal, illumination.

This app supports 3 levels of ‘flash’ [brightness elevation] – I call this ‘shirt-sizing’ – S, M, L.  Below are 4 screen shots of the Flash filter in action: None, Small, Medium, Large.

This filter attempts to be somewhat realistic – it is not just an across-the-board brightness increase. For instance, objects that are very dark in the original scene (such as her handbag or the interior revealed by the doorway in the rear of the scene) only are increased slightly in level, whiile midtones and highlights are raised much more substantially.

Flash: Original

Flash: Small / Medium / Large

Adjust – there are 7 sub-functions within the Adjust edit function; Brightness, Saturation, Hue, Contrast, Sharpness, Tint and Color Temperature. Each function has a slider that is initially centered, moving it left reduces the named parameter, moving it right increases. Once moved off the zero center position, a small “x” on the upper right of the assoiciated icon can be tapped to return the slider to the middle position, effectively turning off any changes. Examples below for each of the sub-functions are shown.

Brightness: Minimum / Original / Maximum

Saturation: Minimum / Original / Maximum

Hue: Minimum / Original / Maximum

Contrast: Minimum / Original / Maximum

Sharpness: Minimum / Original / Maximum

Tint: Minimum / Original / Maximum

Color Temperature: Minimum / Original / Maximum

Color Temperature: Cooler / Original / Warmer

Filters – There are 45 image filters in the Edit section of the app. Some of them are similar or identical in function to the filters of the same name that were discussed in the Live Filter section above. These are contained in 5 groups: Nostalgia, Special, Colorize, Artistic and Distortion. The examples below are similar in format to the presentation of the Live Filters. The source images for these comparisons are imported files (see the note at the beginning of this section for details).

Nostalgia filters:

Nostalgia filter = Coffee

Nostalgia filter = Coffee

The Coffee filter is rather well-named:  it looks like your photo had weak coffee spread over it! You can see from the chart that, as usual for many of the CameraPlusPro filters, increased contrast, crushed blacks and desaturation is the base on which a subtle warm-brown cast is overlayed. The live example shows the increased contrast around her eyes, and the skin tones in both the woman and the man in the background have tended to pale brown as opposed to the original red/yellow/pink.

Nostalgia filter = Retro Red

Nostalgia filter = Retro Red

The Retro Red filter shows increased saturation, a red tint across the board (highlights and lowlights), and does not alter the contrast – note all the steps in the grayscale are mostly discernable – although there is a slight blending/clipping of the top highlights. The overall brightness levels are raised from midtones through the highlights.

Nostalgia filter = Vintage

Nostalgia filter = Vintage

The Vintage filter here in the Edit portion of the app is very similar to the filter of the same name in the Live Filter section. The overall brightness appears higher, but some of that may be due to the different process of shooting with a live filter and applying a filter in the post-production process. This is more noticeable in the live shot as opposed to the charts – a comparision of the “Vintage” filter test charts from the Live Filter section and the Edit section shows almost a dead match. This filter is a warming filter that adds a reddish-brown cast to the image. It increases the contrast some  – this can be seen in the chart in the area of columns 1-2 and rows A-J. The white and black ends of the grayscale are likewise compressed. Any cool pastel colors either turn white or a pale warm shade (look at columns 9-11). The live image shows these effects, note particularly how the man’s blue shirt and shorts change color remarkably. The increase in contrast, coupled with the warming tint, does tend to make skin tones blotchy – note the subject’s face and chest.

Nostalgia filter = Nostalgia

Nostalgia filter = Nostalgia

The Nostalgia filter, like Vintage above, is basically the same filter as the instance offered in the Live Filter section. The main difference is the Live Filter version is more magenta and a bit darker than this filter. Also the cyans tend green more strongly in this version of the filter – check out columns 12-13 in the chart. Some increased contrast, pronounced yellows in the highlights and increased red/blue saturation are also evident.

Nostalgia filter = Retro

Nostalgia filter = Retro

The Retro filter, as in the version in the Live Filter section, attempts to recreate the look of cheap film cameras of the 1960′s and 1970′s. These low quality cameras often had simple plastic lenses, light leaks due to imperfect fit of components, etc. The noticeable chromatic aberrations of the lens and other optical ‘faults’ have now seen a resurgence as a style, and that is emulated with digital filters in this and others shown below. This particular filter shows a general warming, but with a pronounced red shift in the low lights. This is easily observable in the gray scale strip on the chart.

Nostalgia filter = Retro Green

Nostalgia filter = Retro Green

The Retro Green filter is a bit of a twist on Retro, with some of Nostalgia thrown in (yes, filter design is a lot like cooking with spices..)  The lowlights are similar to Nostalgia, with a blue cast, the highlights show the same yellows as both Retro and Nostalgia, the big difference is in the midtones which are now strongly green.

Nostalgia filter = 70s

Nostalgia filter = 70s

The 70s filter gives us some desaturation, no change in contrast, red shift in midtones and lowlights, yellow shift in highlights.

Nostalgia filter = Antique

Nostalgia filter = Antique

The Antique filter is similar to the Antique Live Filter, but is much lighter in terms of brightness. There is a large degree of desaturation, some increase in contrast, significant brightness increase in the highlights, and very slight color shifts at the ends of the grayscale:  yellow in the highlights, blue in the lowlights.

Nostalgia filter = Washed

Nostalgia filter = Washed

The Washed filter here in the Edit section is very different from the filter of the same name in Live Filters. The only real similarity is the strongly yellowed highlights. This filter, like many of the others we have reviewed so far, has a much lighter look (brightness levels raised), a very slight magenta shift, slightly increased contrast, enhanced blues in the lowlights and some increase in cyan in the midtones.

Special filters:

Special filter = XPro

Special filter = XPro

The XPro filter in the Edit functions has a different appearance than the filter of the same name in Live Filters. This instance of the digital emulation of a ‘cross-process’ filter is less contrasty, less magenta, and has more yellow in the highlights. The chart shows the yellows in the highlights, blues in the lowlights, and increased saturation. The live shot reveals the increased white clipping on her dress (due to increased contrast), as well as the crushed blacks (notice the detail of the folds in her leather handbag are lost).

Special filter = Pop

Special filter = Pop

The Pop filter brings the familiar basic tonal adjustments (increased contrast, with crushed whites and blacks, an overall increase in midtone and highlight brightness levels) but this time the lowlights have a distince red/magenta cast, with midtones and highlights tending greenish/yellow. This is particularly evident in the live shot. Look at the black doorway in the original which is now very reddish in the filtered shot.

Special filter = Lomo

Special filter = Lomo

The Lomo filter here in the Edit area is rather different than the same named filter in Live Filters. This particular instance shows increased contrast and saturation, yellowish warming in the highlights, and like some other CameraPlusPro filters, an added spatial effect (the red splotch – in this example the red tint is in the same lower right corner for both chart and woman – if the placement is random, then this is just coincidence – but… it makes it look like the lowlights in the grayscale chart are pushed hard to red:  not so, it’s just that’s where the red tint overlay is this time…). Look at the top of her handbag in the live shot to see that the blacks are not actually shifted red. As with many other CameraPlusPro filters, the whites and blacks are crushed some – you can see on her dress how the highlights are now clipped.

Special filter = Holga

Special filter = Holga

The Holga filter is one where there is a marked similarity between the Live Filter and this instance as an Edit Filter. This version is lighter overall, with a more greenish-yellow cast, particularly in the shadows. The vignette effect is stronger in this Edit filter as well.

Special filter = Diana

Special filter = Diana

The Diana filter is another ‘retro camera’ effect:  based on, wow – surprise, the Diana camera… another of the cheap plastic cameras prevalent in the 1960′s. The vignetting, light leaks, chromatic aberrations and other side-effects of a $10 camera have been brought into the digital age. In a similar fashion to several of the previous ‘retro’ filters discussed already, you will notice crushed blacks & highlights, increased contrast, odd tints (in this case unsaturated highlights tend yellow), increased saturation of colors – and a slight twist in this filter due to even monochrome areas becoming tinted – the silver pendant on her chest now takes on a greenish/yellow tint.

Special filter = Polaroid

Special filter = Polaroid

The Polaroid filter here in the Edit section resembles the effects of the same filter in Live Filters in the highlights (tends yellow with some mild clipping), but diverges in the midtones and shadows. Overall, this instance is lighter, with much less magenta shift in the skin tones. The contrast is not as high as in the Live Filter version, and the saturation is a bit lower.

Special filter = Rust

Special filter = Rust

The Rust filter is really very similar to old-style sepia printing:  this is a post-tint process to a monochrome image. In this filter, the image is first rendered to a black & white image, then colorized with a warm brown overlay. The chart clearly shows this effect.

Special filter = Glamorize

Special filter = Glamorize

The Glamorize filter is a high contrast effect, with considerable clipping in both the blacks and the whites. The overall color balance is mostly unchanged, with a slight increase in saturation in the midtones and lowlights. Thr highlights on the other hand are somewhat desaturated.

Special filter = Hipster

Special filter = Hipster

The Hipster filter follows the same pattern as other filters that have the same name in both the Live Filters section and the Edit section: the Edit version is usually lighter with higher brightness levels, less of a magenta cast in skin tones and lowlights, and a bit less contrast. Still, in relation to the originals, the Hipster has the typical crushed whites and blacks, raised contrast, and in this case an overall warming (red/yellow) of midtones and highlights.

Colorize filters:

Colorize filter = Black & White

Colorize filter = Black & White

The Black & White filter here is almost identical to the effects produced by the same filter in the Live Filter section. A comparison of the chart images shows that. The live shots also render in a similar manner, with as usual the Edit filter being a bit lighter with slightly lower contrast. This is yet another reason to always evaluate a filter with at least two (and the more, the better) different types of source material. While digital filters offer a wealth of possibilities that optical filters never could, there are very fundamental differences in how these filters work.

At a simple level, an optical filter is far more predictable across a wide range of input images than a digital filter. The more complex a digital filter becomes (and many of the filters discussed here that attempt to emulate a multitude of ‘retro’ camera effects are quite complex) the more unexpected results are possible. When you consider that a Wratten #85 warming filter is really very simple (an orange filter that essentially partially blocks bluish/cyan light) – therefore this action will occur no matter what the source image is.

A filter such as Hipster, for example, attempts to mimic what is essentially a series of composited effects from a cheap analog film camera:  chromatic aberration of the cheap plastic lens, spherical lens aberration, light leaks, vignetting due to incomplete coverage of the film (sensor) rectangle, focus anomalies due to imperfect alignment of the focal plane of the lens with the film plane, etc. etc. Trying to mimic all this with mathematics (which is what a digital filter does, it simply applies a set of algorithms to each pixel) means that it’s impossible for even the most skilled visual programmer to fully predict what outputs will occur from a wide variety of inputs.

Colorize filter = Sepia

Colorize filter = Sepia

The Sepia filter is very similar to the Rust filter – it’s another ‘monochrome-then-tint’ filter. This time instead of a reddish-brown tint, the color overlay is a warm yellow.

Colorize filter = Sunset

Colorize filter = Sunset

The Sunset filter brings increased brightness, crushed whites and blacks, increased contrast and an overall warming towards yellow/red. Looks like it’s attempting to emulate the late afternoon light.

Colorize filter = Moss

Colorize filter = Moss

The Moss filter is, well, greenish… It’s a somewhat interesting filter, as most of the tinting effect is concentrated solely on monochromatic midtones. The chart clearly shows this. The live shot demonstrates this as well, the saturated bits keep their colors, the neutrals turn minty-green. Note his shirt, her dress, yellow sign stays yellow, and skin tones/hair don’t take on that much color.

Colorize filter = Lucifer

Colorize filter = Lucifer

The Lucifer filter is – surprise – a reddish warming look. There is an overall desaturation, followed by a magenta/red cast to midtones and lowlights. A slight decrease in contrast actually gives this filter a more faded, retro look than ‘devilish’, and in some ways I prefer this look to some of the previous filters with more ‘retro-sounding’ names.

Colorize filter = Faded

Colorize filter = Faded

The Faded filter offers a desaturated, but contrasty, look. Usually I interpret a ‘faded’ look to mean the kind of visual fading that light causes on a photographic print, where all the blacks and strongly saturated colors fade to a much lighter, softer tone. In this case, much of the color has faded, but the luminance is unchanged (in terms of brightness) and the contrast is increased, resulting in the crushed whites and blacks common to Camera Plus Pro filter design.

Colorize filter = Warm

Colorize filter = Warm

The Warm filter is basically a “plus yellow” filter. Looking at the chart you can see that there is an across-the-board increase in yellow. That’s it.

Colorize filter = Arctic

Colorize filter = Arctic

The Arctic filter is, well, cold. Like several of the other tinted monochromatic filters (Rust, Sepia), this filter first renders the image to a monochrome version, then tints it at all levels with a cold blue color.

Colorize filter = Allure

Colorize filter = Allure

The Allure filter is similar to the Warming filter – an even application of a single color increase – in this case magenta. There is also a slight increase in contrast.

Artistic filters:

Artistic filter = HDR

Artistic filter = HDR

The HDR filter is an attempt to mimic the result from ‘real’ HDR (High Dynamic Range) photography. Of course without true double (or more) exposures, this is not possible, but since some of the ‘look’ that some instances of HDR processing reveal show increased contrast, saturation and so on – this filter emulates some of that. Personally, I believe that true HDR photography should be indistinguishable from a ‘normal’ image – except that it should correctly map a very wide range of illumination levels correctly. A lot of “HDR” images tend to be a bit ‘gimicky’ with excessive edge glow, false saturation, etc. While this can make an interesting ‘special effect’ I think that it would better serve the imaging community if we correctly labeled those images as ‘cartoon’ or some other more accurate name – those filter side-effects really have nothing to do with true HDR imaging. Nevertheless, to complete the description of this filter, it is actually quite ‘color-neutral- (no cast), but does add contrast, particularly edge contrast; and significant vibrance and saturation.

Artistic filter = Fantasy

Artistic filter = Fantasy

The Fantasy filter is another across-the-board ‘color cast’ filter, this time with an increase in yellow-orange. Virtually no change in contrast, just a big shift in color balance.

Artistic filter = Vignette

Artistic filter = Vignette

The Vignette filter is a spatial filter, in that it really just changes the ‘shape’ of the image, not the overall color balance or tonal gradations. It mimics the light fall-off that was typical of early cameras whose lenses had inadequate covering power (the image rendered by the lens did not extend to the edges of the film). There is a tiny loss of brightness even in the center of the frame, but essentially this filter darkens the corners.

Artistic filter = Grunge

Artistic filter = Grunge

The Grunge filter is a combination filter:  both a spatial and tonal filter. It first, like past filters that are ‘tinted monochromatic’ filters, renders the image to black & white, then tints it – in this case with a grayish-yellow cast. There is also a marked decrease in contrast, along with elevated brightness levels. This is easily evident from the grayscale strip in the chart. In the live shot you can see her handbag is now a dark gray instead of black. The spatial elements are then added:  specialized vignetting, to mimic frayed or over-exposed edges of a print, as well as ‘scratches’ and ‘wrinkles’ (formed by spatially localized changes in brightness and contrast). All this combines to offer the look of an old, faded, bent and generally funky print.

Artistic filter = Pop Art

Artistic filter = Pop Art

The Pop Art filter is very much a ‘special effects’ filter. This particular filter is based on the solarization technique. This process (solarization) is in fact a rather complex and highly variable technique. It was initially discovered by Daguerre and others who first pioneered photography in the mid-1800’s. The name comes from the reversal of image tone of a drastically over-exposed part of an image:  in this case, pictures that included the sun in direct view. Instead of the image of the sun going pure white (on the print, pure black in the negative), the sun’s image actually went back to a light gray on the negative, rendering the sun a very dark orb in the final print. One of the very first “optical special effects” in the new field of photography. This is actually cause by halogen ions released within the halide grain by over-exposure diffusing to the grain surface in amounts sufficient to destroy the latent image.

In negatives, this is correctly known as the Sabattier effect after the French photographer, who published an article in Le Moniteur de la Photographie 2 in 1862. The digital equivalent of this technique, as shown in this filter, uses image tonal mapping computation to create high contrast bands where the levels of the original image are ‘flattened’ into distinct and constant brightness bands. This is clearly seen in the grayscale strip in the chart image. It is a very distinctive look and can be visually interesting when used in a creative manner on the correct subject matter.

Artistic filter = Grayscale

Artistic filter = Grayscale

The Grayscale filter is just that:  the rendering of the original image into a grayscale image. The difference between this filter and the Black & White filters (in both Live Filters and this Edit section) is a much lower contrast. By comparing the grayscale strips in the original and filtered chart images, you can see there is virtually no difference. The Black & White filters noticeably increase the contrast.

Artistic filter = Emboss

Artistic filter = Emboss (40%)

Artistic filter = Emboss (100%)

The Emboss filter is another highly specialized effects filter. As can be seen from the chart image, the picture is rendered to a constant monochrome shade of gray, with only contrasting edges being represented by either an increase or decrease in brightness. This creates the appearance of a flat gray sheet that is ‘stamped’ or embossed with the outline of the image elements. High contrast edges are rendered sharply, lower contrast edges are softer in shape. Reading from left to right, a transition from dark to light is represented by a dark edge, from light to dark is shown as light edge. Since each of these Edit filters has an intensity slider, the effect’s strength can be ‘dialed in’ as desired. I have shown all the filters up to now at full strength, for illustrative purposes. Here I have included a sample of this filter at a 40% level, since it shows just how different a look can be achieved in some cases by not using a filter at full strength.

Artistic filter = Xray

Artistic filter = Xray

The Xray filter is yet another ‘monochromatic tint’ filter, with the image first being rendered to a grayscale image, then (in this case) undergoing a complete tonal reversal (to make the image look like a negative), then finally a tint with a dark greenish-cyan color. It’s just a look (since all ‘real’ x-ray films are black and white only), but I’m certain at least one of the millions of people that have downloaded this app will find a use for it.

Artistic filter = Heat Signature

Artistic filter = Heat Signature

The Heat Signature filter is the final filter in this Artistic group. It is illustrative of a scientific imaging method whereby infrared camera images (that see only wavelengths too long for the human eye to see) are rendered into a visual color spectrum to help illustrate relative temperatures of the observed object. In the real scientific camera systems, cooler temperatures are rendered blue, the hottest parts of the image in reds. In between temperatures are rendered in green. Here, this mapping technique is applied against the grayscale. Blacks are blue, midtones are green, highlights are red.

Distortion filters:

The geometric distortion filters are presented differently, since these are spatial filters only. There is no need, nor advantage, to using the color chart test image. I have presented each filter as a triptych, with the first image showing the control as found when the filter is opened within the app, the second image showing a manipulation of the “effects circle” (which can be moved and resized), and the third image is the resultant image after applying the filter. There are no intensity sliders on the distortion filters.

Geometric Filter: Center Offset - Initial / Targeted Area / Result

The Center Offset filter ‘pulls’ the image to the center of the circle, as if the image was on an elastic rubber sheet, and was stretched towards the center of the control circle.

Geometric Filter: Pixelate - Initial / Targeted Area / Result

The Pixelate filter distorts the image inside of the control circle by greatly enlarging the quantization factors in the affected area, causing a large ‘chunking’ of the picture. This renders the affected area virtually recognizable – often used in candid video to obfuscate the identity of a subject.

Geometric Filter: Bulge - Initial / Targeted Area / Result

The Bulge filter is similar to the Center Offset, but this time the image is ‘pulled into’ the control circle, as if a magnifying fish-eye lens was applied to just a portion of the image.

Geometric Filter: Squeeze - Initial / Targeted Area / Result

The Squeeze filter is somewhat the opposite of the Bulge filter, with the image within the control circle being reduced in size and ‘pushed back’ visually.

Geometric Filter: Swirl - Initial / Targeted Area / Result

The Swirl filter does just that:  takes the image within the control circle and rotates it. Moving the little dot controls the amount and direction of the swirl. She needs a chiropractor after this…

Geometric Filter: Noise - Initial / Targeted Area / Result

The Noise filter works in a similar way to the Pixelate filter, only this time large-scale noise is introduced, rather than pixelation.

Geometric Filter: Light Tunnel - Initial / Targeted Area / Result

The Light Tunnel filter is probably a Star Trek shadow – what part of our common culture has not been affected by that far-seeing series? Remember the ‘communicator’?  Flip type cell phones, invented 30 years later, looked suspiciously like that device…

Geometric Filter: Fish Eye - Initial / Result

The Fish Eye filter mimics what a ‘fish eye’ lens might make the picture look like. There is no control circle on this filter – it is a fixed effect. The center of the image is the center of the fish-eye effect. In this case, it’s really not that strong of a curvature effect, to me it looks about like what a 12mm lens (on a 35mm camera system) would look like. If you want to see just how wide a look is possible, go to Nikon’s site and look for examples of their 6.5mm fisheye lens. That is wide!

Geometric Filter: Mirror - Initial / Result

The Mirror filter divides the image down the middle (vertically) and reflects the left half of the image onto the right side. There are no controls – it’s a fixed effect.

Borders:

Borders: Thin White / Rounded Black / Double Frame

Borders: White Frame / Polaroid / Stamp

Borders: Torn / Striped / Grainy

Ok, that’s it. Another iPhone camera app dissected, inspected, respected. Enjoy.

iPhone4S – Section 4b: Camera+ app

March 19, 2012 · by parasam

Camera+  A full-featured camera and editing application. Version described is 3.02

Feature Sets:

  • Light Table design for selecting which photos to Edit, Share, Save or get Info.
  • Camera Functions
    • Ability to split Focus area from Exposure area
    • Can lock White Balance
    • Flash: Off/Auto/On/Torch
    • Front or Rear camera selection
    • Digital Zoom
    • 4 Shooting Modes: Normal/Stabilized/Self-Timer/Burst
  • Camera options:
    • VolumeSnap On/Off
    • Sound On/Off
    • Zoom On/Off
    • Grid On/Off
    • Geotagging On/Off
    • Workflow selection:  Classic (shoot to Lightbox) / Shoot&Share (edit/share after each shot)
    • AutoSave selection:  Lightbox/CameraRoll/Both
    • Quality:  Full/Optimized (1200×1200)
    • Sharing:  [Add social services for auto-post to Twitter, Facebook, etc.]
    • Notifications:
      • App updates On/Off
      • News On/Off
      • Contests On/Off
  • Edit Functions
    • Scenes
      • None
      • Clarity
      • Auto
      • Flash
      • Backlit
      • Darken
      • Cloudy
      • Shade
      • Fluorescent
      • Sunset
      • Night
      • Portrait
      • Beach
      • Scenery
      • Concert
      • Food
      • Text
    • Rotation
      • Left
      • Right
      • Flip Horizontal
      • Flip Vertical
    • Crop
      • Freeform (variable aspect ratio)
      • Original (camera taking aspect ratio)
      • Golden rectangle (1:1.618 aspect ratio)
      • Square (1:1 aspect ratio)
      • Rectangular (3:2 aspect ratio)
      • Rectangular (4:3 aspect ratio)
      • Rectangular (4:6 aspect ratio)
      • Rectangular (5:7 aspect ratio)
      • Rectangular (8:10 aspect ratio)
      • Rectangular (16:9 aspect ratio)
    • Effects
      • Color – 9 tints
        • Vibrant
        • Sunkiss’d
        • Purple Haze
        • So Emo
        • Cyanotype
        • Magic Hour
        • Redscale
        • Black & White
        • Sepia
      • Retro – 9 ‘old camera’ effects
        • Lomographic
        • ‘70s
        • Toy Camera
        • Hipster
        • Tailfins
        • Fashion
        • Lo-Fi
        • Ansel
        • Antique
      • Special – 9 custom effects
        • HDR
        • Miniaturize
        • Polarize
        • Grunge
        • Depth of Field
        • Color Dodge
        • Overlay
        • Faded
        • Cross Process
      • Analog – 9 special filters (in-app purchase)
        • Diana
        • Silver Gelatin
        • Helios
        • Contessa
        • Nostalgia
        • Expired
        • XPRO C-41
        • Pinhole
        • Chromogenic
    • Borders
      • None
      • Simple – 9 basic border styles
        • Thick White
        • Thick Black
        • Light Mat
        • Thin White
        • Thin Black
        • Dark Mat
        • Round White
        • Round Black
        • Vignette
      • Styled – 9 artistic border styles
        • Instant
        • Vintage
        • Offset
        • Light Grit
        • Dark Grit
        • Viewfinder
        • Old-Timey
        • Film
        • Sprockets

Camera Functions

After launching the Camera+ app, the first screen the user sees is the basic camera viewfinder.

Camera view, combined focus & exposure box (normal start screen)

On the top of the screen the Flash selector button is on the left, the Front/Rear Camera selector is on the right. The Flash modes are: Off/Auto/On/Torch. Auto turns the flash off in bright light, on in lower light conditions. Torch is a lower-powered continuous ‘flash’ – also known as a ‘battery-killer’ – use sparingly! Virtually all of the functions of this app are directed to the high-quality rear-facing camera – the front-facing camera is typically reserved for quick low-resolution ID snaps, video calling, etc.

On the bottom of the screen, the Lightbox selector button is on the left, the Shutter release button is in the middle (with the Shutter Release Mode button just to the right-center), and on the right is the Menu button. The Digital Zoom slider is located on the right side of the frame (Digital Zoom will be discussed at the end of this section). Notice in the center of the frame the combined Focus & Exposure area box (square red box with “+” sign). This indicates that both the focus and the exposure for the entire frame are adjusted using the portion of the scene that is contained within this box.

You will notice that the bottle label is correctly exposed and focused, while the background is dark and out of focus.

The next screen shows what happens when the user selects the “+” sign on the upper right edge of the combined Focus/Exposure area box:

Split focus and exposure areas (both on label)

Now the combined box splits into two areas:  an Focus area (square box with bull’s eye), and an Exposure area (round circle resembling the adjustable f-stop ring in a camera lens). The exposure is now measured separately from the focus – allowing more control over the composition and exposure of the image.

In this case the resultant image looks like the previous one, since both the focus and the exposure areas are still placed on the label, which has consistent focus and lighting.

In the next example, the exposure area is left in place – on the label – but the focus area is moved to a point in the rear of the room. You will now notice that the rear of the room has come into focus, and the label has gone soft – out of focus. However, since the the exposure area is unchanged, the relative exposure stays the same – label well lit – but the room beyond still dark.

Split focus and exposure areas, focus moved to rear of room

This level of control allows greater freedom and creativity for the photographer.  [please excuse the slight blurring of some of the screen shot examples – it’s not easy to hold the iPhone completely still while taking a screen shot – which requires simultaneously pressing the Home button and the Power button – even on a tripod]

The next image shows the results of selecting the little ‘padlock’ icon in lower left of the image – this is Lock/Unlock button for Exposure, Focus and White Balance (WB).

Showing 'lock' panel for White Balance (WB), exposure and focus

Each of the three functions (Focus, Exposure, White Balance) can be locked or unlocked independently)

Focus moved back to label, still showing lock panel

In the above example, the focus area has been moved back to the label, showing how the focus now returns to the label, leaving the rear of the room once again out of focus.

The next series of screens demonstrate the options revealed when the Shutter Release Mode button (the little gear icon to the right of the shutter button) is selected:

Shutter type 'Settings' sub-menu displayed, showing 4 options

The ‘Normal’ mode exposes one image each time the shutter button is depressed.

Shutter type changed to Stabilized mode

When the ‘Stabilizer’ mode is selected, the button icon changes to indicate this mode has been selected. This mode is an indication (and an automatic shutter release) of the stability of the iPhone camera once the Stabilizer Shutter Release button is depressed – NOT a true motion-stabilized lens as in some expensive DSLR cameras. You have to hold the camera still to get a sharp picture – this function just helps the user know that the camera is indeed still. Once the Stabilizer Shutter Release is pushed, it glows red if the camera is moving, and text on the screen urges the user to hold still. As the camera detects that motion has stopped (using the iPhone’s internal accelerometer – motion detector) little beeps sound, and the shutter button changes color from red to yellow to green and then the picture is taken.

Shutter type changed to Timer mode - screen shows beginning of 5sec countdown timer

The Self-Timer Shutter Release mode allows a time delay before the actual shutter release occurs – after the shutter button is depressed. The most common use for this feature is a self-portrait (of course you need either a tripod or other method of securing the iPhone so the composition does not change!). This mode can also be useful to avoid jiggling the camera while pressing the shutter release – important in low light situations. The count-down timer is indiated by the numbers in the center of the screen. Once the shutter is depressed, the numbers count down (in seconds) until the exposure occurs. The default time delay is 5 seconds, this can be adjsuted by tapping the number on the screen before the shutter button is selected. The choices are 5, 15 and 30 seconds.

Shutter type changed to Burst mode

The final of the four shutter release modes is the ‘Burst’ mode. This exposes a short series of exposures, one right after the other. This can be useful for sports or other fast moving activity, where the photographer wants to be sure of catching a particular moment. The number of exposures taken is a function of how long you hold down the shutter release – the camera keeps taking pictures as fast as it can as long as you hold down the shutter.

There are a number of things to be aware of while using this mode:

  • You must be in the ‘Classic’ Workflow, not the ‘Shoot & Share’ ( more on this below when we discuss that option)
  • The best performance is obtained when the AutoSave mode is set to ‘Lightbox’ – writing directly to the Camera Roll (using the ‘Camera Roll’ option) is slower, leading to more elapsed time between each exposure. The last option of AutoSave (‘Lightbox & CameraRoll’) is even slower, and not recommended for burst mode.
  • The resolution of burst photos is greatly reduced (from 3264×2448 down to 640×480). This is the only way the data from the camera sensor can be transferred quickly enough – but one of the big differencdes between the iPhone camera system and a DSLR. The full resolution is 8megapixels, the burst resolution is only 0.3megapixels – more than 25x less resolution!

Resultant picture taken with exposure & focus on label

The above shot is an actual unretouched image using the settings from the first example (focus and exposure areas both set on label of the bottle).

Here is an example of how changing the placement of the Exposure Area box within the frame affects the outcome of the image:

exposure area set on wooden desktop - normal range of exposure

exposure area set on white dish - resulting picture is darker than normal

exposure area set on black desk mat - resulting image is lighter than normal

To fully understand what is happening above you need to remember that any camera light metering system sets the exposure assuming that you have placed the exposure area on a ‘middle gray’ value (Zone V). If you place the exposure measurement area on a lighter or darker area of the image the exposure may not be what you envisioned. Further discussion of this topic is outside the scope of this blog – but it’s very important, so if you don’t know – look it up.

The Lightbox

The next step after shooting a frame (or 20) is to process (edit) the images. This is done from the Lightbox. This function is entered by pressing the little icon of a ‘film frame’ on the left of the bottom control bar.

empty Lightbox, ready to import a photograph for editing

The above case shows an empty Lightbox (which is how the app looks after all shots are edited and saved). If you have just exposed a number of images, they will be waiting for you in the Lightbox – you will not need to import them. The following steps are for when you are processing previously exposed images (and it doesn’t matter if they were shot with Camera+ or any other camera app. I sometimes shoot with my film camera, scan the film, import to iPhone and edit with Camera+ in order to use a particular filter that is available).

selection window of the Lightbox image picker

an image selected in the Lightbox image picker, ready for loading into the Lightbox for editing

image imported into the Lightbox, ready for an action

When entering the Edit mode after loading an image, the following screen is displayed. There are two buttons on the top:  Cancel and Done. Cancel returns the user to the Lightbox, abandoning any edits or changes made while in the Edit screen, while Done applies all the edits made and returns the user to the Lightbox where the resultant image can be Shared or Saved to the Camera Roll.

Along the bottom of the screen are two ribbons showing all the edit functions. The bottom ribbon selects the particular edit mode, while the top ribbon selects the actual Scene, Rotation, Crop, Effect or Border that should be applied. The first set of individual edit functions that we will discuss are the Scenes. The following screen shots show the different Scene choices in the upper ribbon.

Scene modes 1 - 5

Scene modes 6 - 9

Scene modes 10 - 14

Scene modes 15 - 17

The ‘Scenes’ that Camera+ offers are one of the most powerful functions of this app. Nevertheless, there are some quirks (mostly about the naming – and the most appropriate way to apply the Scenes, based on the actual content of your image) that will be discussed. The first thing to understand is the basic difference between Scenes and Effects. Both at the most fundamental level transform the brightness, contrast, color, etc of the image (essentially the visual qualities of the image) – as opposed to the spatial qualities of the image that are adjusted with Rotation, Crop and Border. However, a Scene typically adjusts overall contrast, color balance, sometimes modifies white balance, brightness and so on. An Effect is a more specialized filter – often significantly distorting the original colors, changing brightness or contrast in a certain range of values, etc. – the purpose being to introduce a desired effect to the image. Many times a Scene can be used to ‘rescue’ an image that was not correctly exposed, or to change the feeling, mood, etc. of the original image. Another way to think about a Scene is that the result of applying a Scene will still almost always look as if the image had just been taken by the camera, while an Effect very often is clearly an artificially applied filter.

In order to best demonstrate and evaluate the various Scenes that are offered, I have assembled a number of images that show a “before and after” of each Scene type. Within each Scene pair, the left-hand image is always the unadjusted original image, while the right-hand image has the Scene applied. The first series of test images is constructed with two comparisons of each Scene type: the first image pair shows a calibrated color test chart, the second image pair shows a woman in a typical outdoor scene. The color chart can be used to analyze how various ranges of the image (blacks, grays, whites, colors) are affected by the Scene adjustment; while the woman subject image is often a good representation of how the Scene will affect a typical real-world image.

After all of the Scene types are shown in this manner, I have added a number of sample images, with certain Scene types applied – and discussed – to better give a feeling of how and why certain Scene types may work best in certain situations.

Scene = Clarity

Scene = Clarity

The Clarity scene type is one of the most powerful scene manipulations offered – it’s not an accident that it is the first scene type in the ribbon… The power of this scene is not that obvious from the color chart, but it is more obvious in the human subject. This particular subject, while it shows most of the attributes of the clarity filter well, is not ideally suited for application of this filter – better examples follow at the end of this section. The real effect of this scene is to cause an otherwise flat image to ‘pop’ more, and have more visual impact. However, just like in other parts of life – less is often more. My one wish is that an “intensity slider” was included with Scenes (it is only offered on Effects, not Scenes) – as many times I feel that the amount of Clarity is overblown. There are techniques to accomplish a ‘toning down’ of Clarity, but those will only be discussed in Part 5 of this series – Tips & Techniques for iPhonography – as currently this requires the use of multiple apps – which is beyond the scope of the app introduction in this part of the series. The underlying enhancement appears to be a spatially localized increase of contrast, and an increase in vibrance and saturation of color.

Notice in the gray scale of the chart that the edges of each density chip are enhanced – but the overall gamma is unchanged (the steps from white to black remain even and separately identifiable). Look at the color patches – there is an increase in saturation (vivedness of color) – but this is more pronounced in colors that are already somewhat saturated. For instance look at the pastel colors in the range of columns 9-19 and rows B-D:  there is little change in overall saturation. Now look at, for instance, the saturated reds and greens of columns 17-18 and rows J-L:  these colors have picked up noticeabley increased saturation.

Looking at the live subject, the local increase in contrast can easily be seen in her face, with the subtle variations in skin tone in the original becoming much more pronounced in the Clarity scene type. The contrast between the light print on her dress and the gray background is more obvious with Clarity applied. Observe how the wrinkles in the man’s shirt and shorts are much more obvious with Clarity. Notice the shading on the aqua-colored steel piping in the lower left of the image: in the original the square pipes look very evenly illuminated, with Clarity applied there is a noticeable transition from light to dark along the pipe.

Scene = Auto

Scene = Auto

The Auto scene type is sort of like using a ‘point and shoot’ camera set to full automatic – the user ideally doesn’t have to worry about exposure, etc. Of course, in this case since the image has already been exposed there is a limit to the corrections that can be applied! Basically this Scene attempts to ensure full tonal range in the image and will manipulate levels, gamma, etc. to achieve a ‘centered’ look. For completeness I have included this Scene – but as you will notice, and this should be expected – there is almost no difference between the befor and after images.With correctly exposed initial images this is what should happen… It may not be apparent on the blog, but when looking carefully at the color chart images on a large calibrated monitor the contrast is increased slightly at both ends of the gray scale:  the whites and blacks appear to clip a little bit.

Scene = Flash

Scene = Flash

The Flash scene type is an attempt to ‘repair’ an image that was taken in low light without a flash – when it was probably needed. Again, like any post-processing technique, this Scene cannot make up for something that is not there:  areas of shadow in which there was no detail in the original image can at best only be turned into lighter noise… But in many cases it will help underexposed images. The test chart clearly shows the elevation in brightness levels all through the gray scale – look for example at gray chip #11 – the middle gray value of the original is considerably lightened in the right-hand image. This Scene works best on images that are of overall low light level – as you can see from both the chart and the woman areas of the picture that are already well-lit tend to be blown out and clipped.

Scene = Backlit

Scene = Backlit

The Backlit scene type tries to correct for the ‘silhouette’ effect that occurs when strong light is coming from behind the subject without corresponding fill light illuminating the subject from the front. While I agree that this is a useful scene correction, it is hard to perform after the fact – and personally I think this is one Scene that is not well executed. My issue is with the over-saturation of reds and yellows (Caucasian skin tones) that more often than not make the subject look like a boiled lobster. I think this comes from the attempt to raise the percived brightness of an overly dark skin tone (since the most common subject in such a situation is a person standing in front of a brightly lit background). You will notice on the chart that the gray scale is hardly changed from the original (a slight overall brightness increase) – but the general color saturation is raised. A very noticeable increase in red/orange/yellow saturation is obvious:  look at the red group of columns 7-8 and rows A-B. In the original these four squares are clearly differentiated – in the ‘after’ image they have merged into a single fully saturated area. A glance at the woman’s image also shows overly hot saturation of skin tones – even the man in the background has a hot pink face now. So, to summarize, I would reserve this Scene for very dark silhouette situations – where you need to rescue an otherwise potentially unusable shot.

Scene = Darken

Scene = Darken

The Darken scene type does just what it says – darkens the overall scene fairly uniformly. This can often help a somewhat overexposed scene. It cannot fix one of the most common problems with digital photography however:  the clipping of light areas due to overexposure. As explained in a previous post in this series, once a given pixel has been clipped (driven into pure white due to the amount of light it has received) nothing can recover this detail. Lowering the level will only turn the bright white into a dull gray, but no detail will come back. Ever. A quick look at the gray scale in the right-hand image clearly shows the lowering of overall brightness – with the whites manipulated more than the blacks. For instance, chip #1 turns from almost white into a pale gray, while chip #17 shows only a slight darkening. This is appropriate so the blacks in the image are not crushed. You will notice by looking at the colors on the chart that darkening effect is pretty much luminance only – no change in color balance. The apparent increase in reds in the skin tone of the woman is a natural side-effect of less luminance with chrominance held constant – once you remove the ‘white’ from a color mixture the remaining color appears more intense. You can see the same effect in the man’s shirt and the yellow background. Ideally the saturation should be reduced slightly as well as the luminance in this type of filter effect – but that can be tricky with a single filter designed to work with any kind of content. Overall this is a useful filter.

Scene = Cloudy

Scene = Cloudy

The Cloudy scene type appears to normalize the exposure and color shift that occurs when the subject is photographed under direct cloudy skies. This is in contrast to the Shade scene type (discussed next) where the subject is shot in indirect light (open shade) while illuminated from a clear sky. This is mostly a color temperature problem to solve – remember that noon sunlight is approximately 5500°K (degrees Kelvin is a measure of color temperature, low numbers are reddish, high numbers are bluish, middle ‘white’ is about 5000°K). Illumination from a cloudy sky is often very ‘blue’ (in terms of color temperature) – between 8000°K – 10000°K, while open shade is less so, usually between 7000°K – 8000°K. If you compare the two scene types (Cloudy and Shade) you will notice that the image is ‘warmed up’ more with the Cloudy scene type. There is a slight increase in brightness but the main function of this scene type is to warm up the image to compensate for the cold ‘look’ often associated with shots of this type. You can see this occuring in the reddening of the woman’s skin tones, and the warming of the gray values of the sidewalk between her and the man.

Scene = Shade

Scene = Shade

The Shade scene type is similar in function to the Cloudy scene (see above for comparison) but differs in two areas: There is a noticeable increase in brightness (often images exposed in the shade are slightly underexposed) and there is less warming of the image (due to open shade being warmer in color temperature than a full cloudy scene illumination). One easy way to compare the two scene types is to examine the color charts – looking at the surround (where the numbers and letters are) – the differences are easy to see there. A glance at the test shot of the woman shows a definite increase in brightness, as well as a slight warming – again look at the skin tones and the sidewalk.

Scene = Fluorescent

Scene = Fluorescent

The Fluorescent scene type is designed to correct for images shot under fluorescent lighting. This form of illumination is not a ‘full-spectrum’ light source, and as such has some unnatural effects when used to take photographs. Our human vision corrects for this – but film or digital exposures do not – so such photos tend to have a somewhat green/cyan cast to them. In particular this makes light-colored skin look a bit washed out and sickish. The only real change I can see in this scene filter is an increase in magenta in the overall color balance (which will help to correct for the green/cyan shift under fluorescent light). The difference introduced is very small – I think it will help in some cases and may be insufficient in others. It is more noticeable in the image of the woman than the test chart (her skin tones shift towards a magenta hue).

Scene = Sunset

Scene = Sunset

The Sunset scene type starts a slightly different type of scene filter – ones that are apparently designed to make an image look like the scene name, instead of correcting the exposure for images taken under the named situation (like Shade, Cloudy, etc.). This twist in naming conventions is another reason to always really test and understand your tools – know what the filter you are applying does at a fundamental level and you will have much better results. It’s obvious from both the chart and the woman that a marked increase in red/orange is applied by this scene type. There is also a general increase in saturation – just more in the reds than the blues. See the difference in the man’s shirt and shorts to see how the blue saturation increases. Again, like the Backlit filter, I personally feel this effect is a bit overdone – and within Camera+ there is no simple way to remedy this. There are methods, using another app to follow the corrections of this app – these techniques will be discussed in the next of the series (Tips & Techniques for iPhonography).

Scene = Night

Scene = Night

The Night scene type attempts to correct for images taken at night under very low illumination. This scene is a bit like the Flash type – but on steroids! The full gray scale is pushed towards white a lot, with even the darkest shadow values receiving a noticeable bump in brightness. There is also a general increase in saturation – as colors tend to be undersaturated when poorly illuminated. Of course this will make images that are normally exposed look greatly overexposed (see both the chart and the woman), but it still gives you an idea of how the scene filter works. Some better ‘real-world’ examples of the Night scene type follow this introduction of all the scene types.

Scene = Portrait

Scene = Portrait

The Portrait scene type is basically a contrast and brightness adjustment. It’s easy to see in the chart comparison, both in the gray scale and on the color chip chart. Look first at the gray scale: all of the gray and white values from chip #17 and lighter are raised, the chips below #17 are darkened. Chips #1 and #2 are now both pure white, having no differentiation. Likewise with chips #20-22, they are pure black. The area defined by columns 13-19 and rows A-C are now pure white, compared to the original where clear differences can be noted. Likewise row L between columns 20-22 can no longer be differentiated. In the shot of the woman, this results in a lightening of skin tones and increased contrast (notice her black bag is solid black as opposed to very dark gray; the patch of sunlight just above her waist is now solid white instead of a bright highlight). Again, like several scene effects I have noted earlier, I find this one a little overstated – I personally don’t like to see details clipped and crushed – but like any filter, the art is in the application. This can be very effective on a head shot that is flat and without punch. The trick is applying the scene type appropriately. Knowledge furthers…

Scene = Beach

Scene = Beach

The Beach scene type looks like the type of filter first mentioned in Sunset (above). In other words, an effect to make the image look like it was taken on a beach (or at least that type of light!). It’s a little bit like the previous Portrait scene (in that there is an increase in both brightness and contrast – but less than Portrait) but also has a bit of Sunset in it as well (increased saturation in reds and yellows – but again not as much as Sunset). While the Sunset type had greater red saturation, this Beach filter is more towards the yellow. See column #15 in the chart – in the original each square is clearly differentiated, in the right-hand image the more intense yellows are very hard to tell apart. Just to the right, in column #17, the reds have not changed that much. When looking at the woman, you can see that this scene type makes the image ‘bright and yellow/red’ – sort of a ‘beachy’ effect I guess.

Scene = Scenery

Scene = Scenery

The Scenery scene type produces a slight increase in contrast, along with increased saturation in both reds and blues – with blue getting a bit more intensity. Easy to compare using the chart, and in the shot of the woman this can be seen in reddish skin tone, as well as significantly increased saturation in the man’s shirt and shorts. While this effect makes people look odd, it can work well on so-called “postcard” landscape shots (which tend to be flat panoramic views with low contrast and saturation). However, as you will see in the ‘real-world’ examples below, often a different scene or filter can help out a landscape in even a better way – it all depends on the original photo with which you are starting.

Scene = Concert

Scene = Concert

The Concert scene type is oddly enough very similar to the previous scene type (Scenery) – just turned up really loud! A generalized increase in contrast, along with red and blue saturation increase – attempts to make your original scene look like, well, I guess a rock-and-roll concert… Normal exposures (see the woman test shot) come out ‘hot’ (overly warm, contrasty with elelvated brightness) but if you need some color and punch in your shot, or desire an overstated effect this scene type could be useful.

Scene = Food

Scene = Food

The Food scene type offers a slight increase in contrast and a bit of increased saturation in the reds. This can be seen in both the charts and the woman shot. It’s less overdone than several of the other scene types, so keep this in mind for any shot that needs just a bit of punch and warming up – not just for shots of food. And again, I see this scene type in the same vein as Beach, Sunset, etc. – an effect to make your shot look like the feeling of the filter name, not to correct shots of food…

Scene = Text

Scene = Text

The Text scene type is an extreme effect – and best utilized as its name implies – to help render shots of text material come out clearly and legibly. An example of actual text is shown below, but you can see from the chart that this is accomplished by a very high contrast setting. The apparent increase in saturation in the test chart is really more of a result of the high contrast – I don’t think a deliberate increase in saturation was added to this effect.

(Note:  the ‘real-world’ examples referred to in several of the above explanations will be shown at the very end of this discussion, after we have illustrated the remaining basic edit functions (Rotation, Crop, Effects and Borders) in a similar comparative manner as above with the Scene types. This is due to many of the sample shots combining both a Scene and an Effect (one of the powerful capabilities of Camera+) – I want the viewer to fully understand the individual instruments before we assemble a symphony…)

The next group of Edit functions is the image Rotation set.

Rotation submenu

The usual four choices of image rotation are presented.

The Crop functions are displayed next.

group 1 of crop styles

group 2 of crop styles

group 3 of crop styles

The Effects (FX) filters, after the Scene types, are the most complex image manipulation filters included in the Camera+ app. As opposed to Scenes, which tend to affect overall lighting, contrast and saturation -and keep a somewhat realistic look to the image – the Effects filters seriously bend the image into a wide variety of (often but not always) unrealistic appearances. Many of the effects mimic early film processes, emulsions or camera types; some offer recent special filtering techniques (such as HDR – High Dyamic Range photography), and so on.

The Effects filters are grouped into four sections:  Color, Retro, Special and Analog. The Analog filter group requires an in-app purchase ($0.99 at the time of this article). In a similar manner to how Scene types were introduced above, an image comparison is shown along with the description of each filter type. The left-hand image is the original, the right-hand image has the specific Effects filter applied. Some further ‘real-world’ examples of using filters on different types of photography are included at the end of this section.

Color Effects filters

Color Effects filters

Color Filter = Vibrant

The Vibrant filter significantly increases the saturation of colors, and appears to enhance the red channel more than green or blue.

Color Filter = Sunkiss'd

The Sunkiss’d filter is a generalized warming filter. Notice, that in contrast to the Vibrance filter above, even the tinfoil dress on the left-hand dancer has turned a warm gold color – where the Vibrance filter did not alter the silver tint – as that filter has no effect on portions of the image that are monochrome. Also, all colors in Sunkiss’d are moved towards the warm end of the spectrum – note the gobo light effect projected above the dancers: it is pale blue in the original, and becomes a warmer green/aqua after the application of Sunkiss’d.

Color Filter = Purple Haze

The Purple Haze filter does not provide hallucinogenic experiences for the photographer, but does perhaps simulate what the retina might imagine… Increased contrast, increased red/blue saturation and a color shift towards.. well… purple.

Color Filter = So Emo

The So Emo filter type (So Emotional?) starkly increases contrast, shifts color balance towards cyan, and to add a counterpoint to an overall cyan tint there is apparently a narrow band enhancement of magenta – notice the enhancement of the tulle skirt on the center dancer that should otherwise be almost monochromatic with addition of so much cyan shift in the color balance. However, the flesh tones of the dancers’ legs (more reddish) are rendered almost colorless by the cyan tint; this shows that the enhancement is narrow-band, it does not include red.

Color Filter = Cyanotype

The Cyanotype effects filter is reminiscent of early photogram techniques (putting plant leaves, etc. on photo paper sensitized with the cyanotype process in direct sunlight to get a silhouette exposure). This is the same process that makes blueprints. Later it was used (in a similar way as sepia toning) to tint black & white photographs. In the case of this effects filter, the image is first rendered to monochrome, then subsequently tinted with a slightly yellowish cyan color.

Color Filter = Magic Hour

The Magic Hour filter attempts to make the image look like it was taken during the so-called “Magic Hour” – the last hour before sunset – when many photographers feel the light is best for all types of photography, particularly landscape or interpretive portraits. Brightness is raised, contrast is slightly reduced and a generalized warming color shift is applied.

Color Filter = Redscale

The Redscale effects filter is a bit like the previous Magic Hour, but instead of a wider spectrum warming, the effect is more localized to reds and yellows. The contrast is slightly raised, instead of lowered as for Magic Hour, and the effect of the red filter can clearly be seen on the gobo light projected above the dancers:  the original cyan portion of the light is almost completely neutralized by the red enhancement, leaving only the green portion of the original aqua light remaining.

Color Filter = Black White

The Black & White filter does just what it says: renders the original color photograph into a monochrome only version. It looks like this is a simple monochrome conversion of the RGB channels (color information deleted, only luminance kept). There are a number of advanced techniques for rendering a color image into a high quality black & white photo – it’s not as simple as it sounds. If you look at a great black and white image from a film camera, and compare it to a color photograph of the same scene, you will know what I am saying. There are specialized apps for taking monochrome pictures with the iPhone (one of which will be reviewed later in this series of posts); and there is a whole set of custom filters in Photoshop devoted to just this topic – getting the best possible conversion to black & white from a color original. In many cases however a simple filter like this will do the trick.

Color Filter = Sepia

The Sepia filter, like Cyanotype, is a throwback to the early days of photography – before color film – when black & white images were toned to increase interest. In the case of this digital filter, the image is first turned into monochrome, then tinted with a sepia tone via color correction.

Retro Effects filters

Retro Effects filters

Retro Filter = Lomographic

The Lomographic filter effect is designed to mimic some of the style of photograph produced by the original LOMO Plc camera company of Russia (Leningrad Optical Mechanical Amalgamation). This was a low cost automatic 35mm film camera. While still in production today, this and similar cameras account for only a fraction of LOMO’s production – the bulk is military and medical optical systems – and are world class… Due to the low cost of components and production methods, the LOMO camera exhibited frequent optical defects in imaging, color tints, light leaks, and other artifacts. While anathema to professional photographers, a large community that appreciates the quirky effects of this (and other so-called “Lo-Fi” or Low Fidelity) cameras has sprung up with a world-wide following. Hence the Lomographic filter…

While, like all my analysis on Scenes and Effects, I have no direct knowledge of how the effect is produced, I bring my scientific training and decades of photographic experience to help explain what I feel is a likely design, based on empirical study of the effect. That said, this effect appears to show increased contrast, a greenish/yellow tint for the mid-tones (notice the highlights, such as the white front stage, stay almost pure white). A narrow-band enhancement filter for red/magenta keeps the skin tones and center dancer’s dress from desaturating in the face of the green tint.

Retro Filter = '70s

The ’70s effect is another nod to the look of older film photographs, this one more like what Kodachrome looked like when the camera was left in a hot car… All film stock is heat sensitive, with color emulsions, particularly older ones, being even more so. While at first this filter has a resemblance to the Sunkiss’d color filter, the difference lies in the multi-tonal enhancements of the ’70s filter. The reds are indeed punched up, but that’s in the midtones and shadows – the highlights take on a distinct greenish cast. Notice that once the enhanced red nulled out the cyan in the overhead gobo projection, then the remaining highlights have turned bright green – with a similar process occuring on the light stage surface.

Retro Filter = Toy Camera

The Toy Camera effects filter emulates the low cost roll-film cameras of the ’50s and ’60s – with the light leaks, uneven processing, poor focus and other attributes often associated with photographs from that genre of cameras. Increased saturation, a slightly raised black level, spatially localized contrast enhancement (a technique borrowed from HDR filtering) – notice the slight flare on the far right over the seated woman’s head become a bright hot flare in the filtered image, and streaking to simulate light leakage on film all add to the multiplicity of effects in this filter.

Retro Filter = Hipster

The Hipster effect is another of the digital memorials to the original Hipstamatic camera – a cheap all plastic 35mm camera that shot square photos. Copied from an original low-cost Russian camera, the two brothers that invented it only produced 157 units. The camera cost $8.25 in 1982 when it was introduced. With a hand-molded plastic lens, this camera was another of the “Lo-Fi” group of older analog film cameras whose ‘look’ has once again become popular. As derived by the Camera+ crew, the Hipster effect offers a warm, brownish-red image. Achieved apparently with raised black levels (a common trait of cheap film cameras, the backs always leaked a bit of light so a low level ‘fog’ of the film base always tended to raise deep blacks [areas of no light exposure in a negative] to a dull gray); a pronounced color shift towards red/brown in the midtones and lowlights; and an overall white level increase (note the relative brightness of the front stage between the original and the filtered version),

Retro Filter = Tailfins

The Tailfins retro effect is yet another take on the ’50s and ’60s – with an homage to the 1959 Cadillac no doubt – the epitomy of the ‘tailfin era’. It’s similar to the ’70s filter described above, but lacks the distinct ‘overcooked Kodachrome’ look with the green highlights. Red saturation is again pushed up, as well as overall brightness. Once again blacks are raised to simulate the common film fog of the day. Lowered contrast finishes the look.

Retro Filter = Fashion

The Fashion effects filter is an interesting and potentially very useful filter. Although I am sure there are styles of fashion photography that have used this muted look, the potential uses for this filter extend far beyond fashion or portraiture. Essentially this is a desaturating filter that also warms the lowlights more than the highlights. Notice the rear wall – almost neutral gray in the original, a very warm gray in the filtered version. The gobo projected light, the greenish-yellow spill on the ceiling, the center dancer’s dress – all greatly desaturated. The contrast appears just a bit raised:  the white front stage is brighter than the original version, and the black dress of the right-hand dancer is darker. With so many photos today – and filters – that tend to make things go pop! bang! and sparkle! it’s sometimes nice to present an image that is understated, but not cold. This just might be a useful tool to help tell that story.

Retro Filter = Lo-Fi

The Lo-Fi is another retro effect filter that is similar in some respects to the Toy Camera filter reviewed above, but does not express the light streak and obvious film fog artifacts. It again provides an unnatural intensity of color – this through greatly increased saturation. There is also an increase in contrast – note the front stage is nearly pure white and the ceiling to the right of the gobo projection has gone almost pure black. There is a non-uniform assignment of color balance and saturation, dependent on the relative luminance of the original scene. The lighter the original scene, the less saturation is added:  compare the white stage to the dark gray interior of the large “1” on the back wall.

Retro Filter = Ansel

The Ansel filter is of course a tip of the hat to the iconic Ansel Adams – one of the premier black & white photographers ever. Although… Ansel would likely have something to say about separation of gray values in the shadows, particularly around Zones II – III.  Compared to the ‘Black & White’ color filter discussed earlier, this filter is definitely of a higher contrast. Personally, I think the blacks are crushed a bit – most of the detail is lost in the black dress, and the faces of the dancers are almost lost now in dark shadow. But for the right original exposure, this filter will offer more dyanmism than the “Black & White” filter.

Retro Filter = Antique

The Antique effects filter is in the same vein as Sepia and Cyanotope: a filter that first extracts a monochrome image from the color original, then tints it – in this case with a yellow cast. The contrast is increased as well.

Special Effects filters

Special Effects filters

Special Filter = HDR @ 100%

Special Filter = HDR @ 50%

The HDR Special filter is, along with the Clarity Scene type, one of the potentially more powerful filters in this entire application. Because of this (and to demonstrate the Intensity Slider function) I have inserted two examples of this filter, one with the intensity set at 100%, and one with the intensity at 50%. All of the Effects filters have an intensity control, so the relative level of the effect can be adjusted from 0-100%. All of the other examples are shown at full intensity to discuss the attributes of the filter with the greatest ease, but many times a lessening of the intensity will give better results. That is nowhere more evident than with the HDR effect. This terms stands for High Dynamic Range photography. Normally, this can only be performed with multiple exposures of precisely the same shot in the camera – then through complex post-production digital computations, the two (or more) images are superimposed on top of each other, with the various parts of the images seamlessly blended. The whole purpose of this is to make a composite image that has a greater range of exposure than was possible with the taking camera/sensor/film.

The usual reason for this is an extreme range of brightness. An example:  if you stand in a dimly lit barn and shoot a photograph out the open barn door at the brightly lit exterior at noon, the ratio of brightness from the barn interior to the exterior scene can easily approach 100,000:1 – which is impossible for any medium, whether film or digital, to capture in a single exposure. The widest range film stock ever produced could capture about 14 stops – about 16,000:1. And that is theoretical – once you add the imperfections of lens, the small amount of unavoidable base fog and development noise, 12 stops (about 4,000:1) is more realistic. With CCD arrays (high quality digital sensors as found in expensive DSLR cameras, not the CMOS sensors used in the iPhone), it is theoretically possible to get about the same. While the top of the line DSLRs boast a 16-bit converter, and do output 16-bit images, the actual capability of the sensor is not that good. I personally doubt it’s any better than the 12 stops of a good film camera – and that only on camera backs costing the same as a small car…

What this means in practicality is that to capture such a scene leads to one of two scenarios:  either the blacks are underexposed (if you try to avoid blowing out the whites); or the white detail is lost in clipping if you try to keep the black shadow detail in the barn visible. The only other option (employed by professional photographers with a budget of both time and money) is to light the inside of the barn sufficiently that the contrast of the overall scene is brought within range of the taking film or digital array.

With HDR, a whole new possibility has arrived: take two photographs (identical, must line up perfectly so camera has to be on a tripod, and no motion in the scene is allowed – a rather restrictive element, but critical) – then with the magic of digital post-processing, the low-light image (correctly exposed for the shadows, so the highlights are blown out) and the hi-light image (correctly exposed for the brightly lit part of the scene, so the inside of the barn is just solid black with no detail) are combined into a composite photograph that has incredible dynamic range. There is a lot more to it than this, and you can’t get around the display part of the equation (how do you then show an image that has 16 or more stops of dynamic range on a computer monitor that has at best 10 stops of range? or worse yet, ink jet printers, that even on the best high gloss art paper may be able to render 6 stops of dynamic range? We’ll leave those questions for my next part of this blog series, but for now it’s enough to understand that high dynamic range exposures (HDR) are very challenging for the photographer.

So what exactlty IS an HDR filter? Obviously it cannot duplicate the true HDR technique (multiple exposures)… [First, to be clear, there are different types of “HDR filters” – for instance the very complex one in Photoshop is designed to work with multiple source images as discussed above – here we are talking about the HDR filter included with Camera+, and what it can, and cannot, do). The type of filtering process that appears to be used by the HDR filter in this app is known as a “tone mapping” filter. This is actually a very complex process, chock full of high mathematics, and if it weren’t for the power of the iPhone hardware and core software this would be impossible to do on anything but a desktop computer. Essentially, through a process of both global and local tone mapping using specific algorithms, an output image is derived from the input image. As you can see from the results in the right hand images, tone mapping HDR has a unique look. It tends to enhance local contrast, so image sharpness is enhanced. A side effect – that some like and others don’t – is an apparent ‘glow’ around the edges of dark objects in the scene when they are in front of lighter objects. In these examples, look around the edges of the black dress, and the edges of the black outline of the “1” on the back wall. Notice also that in the original photo, the white stage looks almost smooth, in the resultant filtered image, you can see every bit of dust and footscrapes from the models. The overall brightness of the image is enhanced, but nothing is clipped. Due to the enhancement of small detail, noise in low light areas (always an issue with digital sensors) is increased. Look at the area of the ceiling to the right of the projected gobo image:  in the original the low lit area looks relatively smooth, in the filtered image there are many more mottling and other noise artifacts. Due to the amount of detail added, side effects, etc. it is often desired to not ‘overdo’ the tone mapping effect. This can clearly be shown with the second set of comparisions, which has the intensity of the effect set to 50% instead of 100%.

Special Filter = Miniaturize

The Special filter Miniaturize initially confused me – I didn’t understand the naming of this filter in reference to its effects: this filter is very similar to the Depth of Field filter which will be discussed shortly. Essentially this filter increases saturation a bit, and then applies blurring technique to defocus the upper third and lower third of the image, leaving the middle third sharp. A reader of my inital release of this section was kind enough to point out that this filter is attempting to mimic the planar depth-of-field effect that happens when the lens is tilted about the axis of focus. With a physical tilt-shift lens, the areas of soft focus are due to one area of the image being too far to be in focus, the other area being too near to be in focus. This technique is used to simulate miniature photography, hence the filter name. Thanks to darkmain for the update.

Special Filter = Polarize

The Polarize filter is another somewhat odd name for the actual observed effect – since polarizing filtering must take place optically – there is no way to electronically substitute this. Polarizing filters are often used to reduce reflections (from windows, water surface, etc.) – as well as allow us to see 3D movies. None of these techniques are offered by this filter. What this one does do is to substantially increase the contrast, add significant red/blue saturation – but, like the earlier Lo-Fi filter the increase in saturation is inversely proportional to the brightness of the element in the scene: dark areas get increased saturation, light areas do not.

Special Filter = Grunge

The Grunge effect does have a name that makes sense! Looking like the photo was taken through a grungy piece of glass, it has a faded look that is somewhat realistic of old, damaged print photos. The apparent components of this filter are:  substantial desaturation, significant lightening (brightness level raised), a golden/yellow tint added, then the ‘noise’ (scratches).

Special Filter = Depth of Field

The Depth of Field effect is, as mentioned, very similar to the Miniaturize effect. The overall brightness is a bit lower, and the other main difference appears to be a circular area of sharpness in the center of the frame, as opposed to the edge to edge horizontal band of sharpness apparent with the Miniaturize filter. Check the focus of the woman seated on the far right in the two filters and you’ll see what I mean.

Special Filter = Color Dodge

The Color Dodge special filter has me scratching my head again as far as naming goes… In photographic terminology, “dodge” means to hold back, to reduce – while “burn” means to increase. These are techniques originally used in darkroom printing (actually one of the first methods of tone mapping!) to locally increase or decrease the light falling on the print in order to change the local contrast/brightness. In the resultant image from this filter, red saturation has not just been increased, it has been firewalled! Basically, areas in the original image that had little color in them stayed about the same, areas that have significant color values have those values increased dramatically. There is additionally an increase in overall contrast.

Special Filter = Overlay

The Overlay effect has the same contrast and saturation functions as the previous Color Dodge filter, but the saturation is not turned up as high (gratefully!). In addition, there is a pronounced vignette effect – easy to see in the bottom of the frame. It’s circular, just harder to see in this particular image at the top. Like the rest of the effects filters, the ability to reduce the intensity of this effect can make it useful for situations that at first may not be obvious. For instance, since the saturation only works on existing chroma in the image, if one applies this image to a monochrome image now you have a variable vignetter filter – with no color component…

Special Filter = Faded

The Faded special effect filter does just what it says… this is a simple desaturating filter with no other functions visible. With the ability to vary the intensity of desaturation it makes for a powerful tool. Often one would like to just take a ‘bit off the top’ in terms of color gain – digital sensors are inherently more saturated looking than many film emulsions – just compare (if you can, not that many film labs left…) a shot taken of the same scene with both Ektachrome transparency film and the same scene with the iPhone.

Special Filter = Cross Process

The Cross Process is a true special effect! The name comes from a technique, first discovered by accident, where film is processed in a chemical developer that was intended for a different type of film. While the effect in this particular filter is not indicitive of any particular similar chemical cross-process, the overall effect is similar:  high contrast, unnatural colors, and a general ‘retro’ look that has found an audience today. Just like with the chemical version of cross-processing, the results are unpredictable – one just has to try it out and see. Of course, with film, if you didn’t like it… tough.. go reshoot… with digital, just back up and do something else….

Analog Effects filters

Analog Effects filters

Analog Filter = Diana

The Diana effect is based on, wow – surprise, the Diana camera… another of the cheap plastic cameras prevalent in the 1960’s. The vignetting, light leaks, chromatic aberrations and other side-effects of a $10 camera have been brought into the digital age. In a similar fashion to several of the previous ‘retro’ filters discussed already, you will notice raised blacks, slight lowering of contrast, odd tints (in this case unsaturated highlights tend yellow), increased saturation of colors – and a slight twist in this filter due to even monochrome areas becoming tinted – the silver dress (which stayed silver in even some of the strongest effects discussed above) now takes on a greenish/yellow tint.

Analog Filter = Silver Gelatin

The Silver Gelatin effect, based on the original photochemical process that is over 140 years old – is a wonderful and soft effect for the appropriate subject matter. While the process itself was of course only black & white, the very nature of the process (small silver molecules suspended in a thin gelatin coating) caused fading relatively soon after printing. The gelatin fades to a pale yellow, and the silver (which creates the dark parts of the print) tended to turn a purplish color instead of the original pure black.

Analog Filter = Helios

The Helios analog effect, while it’s possible that it was named for the Helios lens that was fabricated for the Russian “Zenit” 35mm SLR camera in 1958 – is just as likely to be called this due to the burning-fire red tint of virtually the entire frame. In a similar manner to other filters we have discussed, the tinting (and this is clearly another example of a tinted monochrome extraction from the original color image) is based on relative luma values:  near whites and near blacks are not tinted, all other mid-range values of gray are tinted strongly red. It’s an interesting technique, but personally I would have only sparing use for this one.

Analog Filter = Contessa

The Contessa effect is named after one of the really great early 35mm Zeiss/Ikon cameras, produced in the late 1940’s. The effect as it exists here is actually not true to the Contessa:  this original film camera would not have caused the vignetting seen – not with one of the world’s greatest lenses attached! However, that’s immaterial, it’s just the name… what we can say about this filter is that obviously it’s another black & white extraction from the color original – but it adds a sense of ‘old time photograph’ with the vignette, the staining/spotting on the sides of the image, and the very slight warm tint – really appears to look faded as opposed to an actual tint. It’s a nice filter, I would adjust it a bit to add more detail/contrast in the dancers’ faces (left and middle dancers’ faces are a bit dark) – but a nice addition to the toolbox.

Analog Filter = Nostalgia

The Nostalgia effect is now reaching into true ‘special effects’ territory. With a cross process look to start with (similar to Diana and Cross Process), some added saturation in the reds, and then the ‘fog’ effect around the perimeter of the frame – this is leaving photorealism behind…

Analog Filter = Expired

The Expired analog effect is a rather good copy of what film used to look like when you left it in the glove box of your car in the summer… or just plain let it get too old. The look created here is just one of many, many possible effects from expired film – it’s a highly unpredictable entity. In this filter, we have strong red saturation increase – again, with no color in the front of the white stage, nothing to saturate… The overall brightness is raised, contrast is lowered, and a light streak is added.

Analog Filter = XPRO C-41

The XPRO C-41 effect is another cross-process filter. This one is loosely based on what happens when you process E-6 film (color transparency) with color negative developer (C-41). Whites get a bit blown out, light areas tend to greenish, with darker areas tending bluish. The red saturation is (I believe) just something these software developers added – I’ve personally never seen this happen in chemical cross processing.

Analog Filter = Pinhole

The Pinhole analog effect is based, of course, on the oldest camera type of all. With major vignetting, considerable grain, monochrome only, enhanced contrast and lowered brightness, this filter does a fair job imitating what an iPhone would have produced in 1850 (when the first actual photograph was taken with a pinhole camera). The issue was that of a photosenstive material – the pinhole camera has been around for well over a thousand years (the Book of Optics published in 1021AD describes it in detail).

Analog Filter = Chromogenic

The Chromogenic analog effect is based on the core methodology of all modern color film emulsions: the coupling of color dyes to exposed silver halide crystals. All current photochemical film emulsions use light-sensitive silver crystals for exposure to light. To make color, typically 3 layers on the film (cyan, yellow, magenta) are actually specialzed chromogenic layers where the dye colors attach themselves to exposed silver crystals in that layer only. This leads to the buildup of a color negative (or positive) by the ‘stacking’ of the three layers to make a completed color image. Very early on, during the experimentation that led to this development, the process was not nearly as well defined – and this filter is one software artist’s idea of what an early chromogenic print may have looked like. In terms of analysis, the overall cast is reddish-brown, with enhanced contrast, slightly crushed blacks and very desaturated colors (aside from the overall tint).

The Border variations

Simple Border styles

Styled border styles

There are, in addition to the “No Border” option, 9 simple borders and 9 styled borders.

‘Real World’ examples using Scenes and Effects

The following examples show some various images, each processed with one or more techniques that have been introduced above. In each case the original image is shown on the left, the processed image is shown on the right. Since, just like in real life, we often learn more from our mistakes than what we get right the first time – I have included some ‘mistakes’ to demonstrate things I believe did not work so well.

Retro Filter = Ansel

The Ansel filter on this subject has too much contrast – there is no detail in the dress and the subtle detail reflected in the glass behind her is washed out.

Scene = Concert

The Concert filter used here looks unnatural:  skin tones too red. It does make the reflections in the glass pop out though…

Scene = Clarity

The Clarity scene is mostly successful here:  improved detail in her dress, the reflections in the window are clearer, the detail in the stone floor pops more. I would opt for a bit less saturation in her skin tones, particularly the legs – the best technique here would be to ‘turn down’ the Clarity a bit. This can be done, but not within Camera+ (at this time).

Special Filter = Overlay

The Overlay filter as used here offers another interpretation of the scene. The slight vignetting helps focus on the subject, the floor is now defocused, the background reflection in the glass behind her is lessened – the only thing I would like to see improved is her dress is a bit dark – hard to see the detail.

Scene = Portrait

The Portrait scene punches up the contrast, and in this case works fairly well. The floor is a bit bright, and it’s a personal decision if the greater detail revealed in the reflection behind the subject is distracting or not… The upper half of her dress is a bit dark due to the increased contrast, it would be nice to see more detail there.

Scene = Shade

This Shade scene applied shows the effects rather well: the scene is warmed up and the brightness is slightly raised.

Analog Filter = Silver Gelatin

The Silver Gelatin effect is demonstrated well here: blacks are a bit purple, all the whites/grays go a bit yellow. It’s a nice soft look for the right subject matter.

Scene = Backlit

The Backlit scene helps add fill to the otherwise underexposed subject. Since in this case she is standing in open shade (very cool in terms of color temperature), the tendency for this Scene to make skin tones too warm is ok. The background is blown out a bit though.

Scene = Food

In this version, the Food scene is used, well, not for food… it doesn’t add as much fill light to the subject as Backlit, but the background isn’t as overexposed either.

Scene = Backlit

Here’s an example of using the Backlit scene for a subject that is not a person – rather for the whole foreground that is in virtual silhouette. It helps marginally, and does tend to wash out the sky some. But the path and the parked cars have more visibility.

Scene = Backlit

Here is the Backlit scene used in the traditional manner – and as was discussed when this scene was introduced above, I find the skin tones just too red. It does fix the lighting however. All is not lost – once we move on to other techniques to be discussed in a future post:  using another app for editing the results of Camera+. For instance, if we now bring this image into PhotoForge2 and apply color correction and some desaturation we can tone down the red skin and back off the overly saturated colors of their tops.

Scene = Backlit

Here’s another example of the Backlit scene. It does again resolve the fill light issue, but once again oversaturates both the skin tones and the background.

Scene = Backlit

Here is Backlit scene used to attempt to fix this shot where insufficient fill light was available on the subject.

Scene = Clarity

This shows the Clarity scene used to help the lack of fill light. I think it works much better than Backlit in this case. I would still follow up with raising the black levels to bring out details in her shirt.

Scene = Beach

Here are three versions of another backlit scene, with different solutions: the first one uses the Beach scene…

Scene = Flash

This version uses Flash…

Scene = Clarity

and the final version trys Clarity. I personally like this one the best, although I would follow up with raising the deep blacks just a bit to bring out the first girl’s top and pants’ detail.

Scene = Beach

This is a woman at the beach… showing what the Beach scene will do… in my opinion, it doesn’t add anything, and has three issues:  the breaking wave is now clipped, with loss of detail in the white foam, the added contrast reduces the detail in her shirt and pants, and the sand at the bottom of the image has lost detail and become blocky. This exemplifies my earlier comment on this type of scene filter:  use it to change the lighting of your image to ‘look like it was shot at the beach’, not fix images that were taken at the beach…

Scene = Clarity

Here once again is our best friend Clarity… this scene really brings out the detail in the waves, sand and her clothes. It’s a great use of this filter, and shows the added ‘punch’ that Clarity can often bring to a shot that is correctly exposed, but just a bit flat.

Scene = Beach, followed by Special Filter = Overlay @ 67%

Now here is a very different interpretation of the same original shot. It all goes to what story you want to tell with your shot. The Clarity version above is a better depiction of the scene that either the original or the version using Beach, but the method shown above (using the Special filter Overlay, at 67% intensity) brings a completely different feeling to the shot. The woman becomes the central figure, with the beach only a hint of the surrounding…

Scene = Scenery

Using the tradional approach… the Scenery scene on, well, scenery…  Doesn’t work well – mid-ground goes dark, mountains in rear too blue, foreground bush loses detail and snap.

Scene = Shade

Here is the same scene using Shade. It does bring out the detail in the middle of the image, and warm up the reflection of the sky in the lake.

Scene = Sunset

Another view, this time using Sunset. Here we have many of the same issues as the first shot did using the Scenery version.

Scene = Beach

Now here I have used the Beach scene type. Although maybe not an intuitive choice, I like the results:  the lake has a warmer reflection of the sky, the contrast between the foreground bush and the middle area is increased, but without losing detail in the middle trees; the mountains in the rear have picked up detail, and even the shore on the left of the lake has more punch. Know your tools…

Scene = Portrait

Next shown are five different versions of a group with some challenging parameters:  white dresses (that pick up reflected light), dark pants and jacket on the man, theatrical lighting (it’s actually a white rug!), and bright backlighting on the left. This first version, using Portrait, with its increased contrast, helps the dresses to a more pure white look, but now the man’s head blends right into the picture – not enough black detail to separate the objects.

Special Filter = HDR

Here is a version using the special filter HDR. Very stylized. Does clearly separate all the details, the picture on the wall is now visible, and easily separated from the man’s head. The glow and the heavy tinting of the model’s dresses is just part of the ‘look’…

Special Filter = Faded @ 50%

As overstated as the last version may have been, this one goes the other way. Using the special filter Faded (at 50% intensity), the desaturation afforded by this method removes the tinting of the white dresses (they pick up the turquoise lighting), and the skin tones look more natural. Maybe a bit flat…

Scene = Clarity

Here is the Clarity scene type.While it does separate out his head from the picture again, the enhanced edges don’t really work as well in this shot. The increased local saturation actually causes the rug in the foreground to blend together – the original has more detail. This is one of the potential side-effects of this filter – when the source has highly saturated colors to start with some weird things can happen.

Scene = Beach

And the last version, using the Beach scene type. The dresses have punch, the skin tones are warmer, but the higher contrast once again merges his head with the picture. The lighting on the rug also looks overdone.

Scene = Scenery

This is a typical landscape shot, treated with the Scenery filter. Doesn’t work. Mountains have gone almost black, sea has lost it’s shading and beautiful turquoise color, the rocks in the foreground have gone harsh.

Scene = Clarity

Now here’s Clarity used on the same scene.This scene type brings out all the detail without overwhelming any one area. The only two minor faults I would point out is the small ‘halo’ effect in the sky near the edges of the mountains, and the emerald area of the ocean (just above the rocks, next to the foam on the shore) is a little oversaturated. But all in all, a much better filter than Scenery – for this shot. It’s all in using the right tool for the right job.

Scene = Clarity

Now as good as Clarity can be for some things, here is causes a very different effect. Not to say it’s wrong – if you are looking for posterization and noise, then this can be a great effect.

Scene = Darken

Although the Darken scene may not seem at all what one would choose on an already poorly lit scene, it focuses attention purely on the subject, and reduces some of the noise and mottling in her top.

Special Filter = Faded @ 33%

Now here is an interesting solution: using the special filter Faded (at 33% intensity) to reduce the saturation of the scene. This immediately brings out a more natural modeling of her face, makes her right hand look less blocky, and brings a more natural look to the subject in general.

Scene = Clarity

A sunset scene using the Clarity filter. In this case, Clarity is not our BFF… the brick goes oversaturated, the shadows in the foreground are just too much -the eye gets confused, doesn’t know where to look.

Scene = Darken

Here, the Darken scene type is tried. Not much better than Clarity, above. (Hint: sometimes the best result is to leave things alone… a properly exposed and composed image often is perfect as it stands, without additional meddling…)

Scene = Sunset

Here we have a number of different expressions of a train leaving the station at sunset… this one using the Sunset scene type. While it does add some color to the sky, most of the detail in the shadows is now gone.

Scene = Clarity

This version shows the use of Clarity. Detail that was barely visible now pops out. The shot now is almost a bit too busy – there is so much extraneous detail to the right and left of the train that the focus of the moment has changed…

Special Filter = HDR (100%)

Here’s a very different version, using HDR at full intensity. Stylized – tells a certain story – but the style is almost overwhelming the image.

Special Filter = HDR @ 30%

This is HDR again, but this time at 30% intensity.What a difference! I feel this selection is even better than Clarity – detail in the middle of the shot is visible, but not detracting from the train. There is now just enough information in the shadows to round out the shot, yet not pull the eye from the story.

Scene = Cloudy

The difference between the Cloudy and Shade scene types is useful to understand. Here are two subjects standing in open shade – i.e. only illiminated by open sky that has no clouds. This version is filtered with the Cloudy scene type. Note that the back wall has changed hue from the original (gone warmer) as has the street. The subjects are still a bit dark as well.

Scene = Shade

Here is the same shot, processed with the Shade scene type. The brightness is improved, the color temperature is not warmed up as much, and overall this is a better solution. (Well, after all, they were standing in the shade 🙂

Scene = Cloudy

Here is another pair of comparisons between the Cloudy and Shade scene type filters. This choice was less obvious, as the hostess was standing just outside the entrance to a restaurant, in partial shade; but the sky was very overcast – a ‘cloudy’ illumination. Notice, that since the Cloudy filter warms the scene more than the Shade filter does, her skin tone has warmed up considerably, as has her sheer top and and the menu. The top and menu are also a bit clipped, losing detail in the highlights.

Scene = Shade

Here is the ‘Shade’ version. Her skin is not as warm, and the top and menu retain more of their original whiteness. The white levels are better as well, with less clipping on the menu and the left side of her top. This shows that often you must try several filter types and make a selection based on the results – this could have easily gone either way, given the nature of the lighting.

Scene = Cloudy

College campus, showing the use of the Cloudy filter. Here this choice is clearly correct. The sky is obviously cloudy <grin> and the resultant warmth added by the filter is appreciated in the scene.

Scene = Shade

This version, using the Shade scene type, is not as effective. The scene is still a bit cold, and the additional brightness added by this filter makes the sky overly bright – the general illumination now somewhat contradicts the feeling of the scene – a cool and cloudy day.

Scene = Concert

We discussed learning from our mistakes… here is why you usually don’t want to use the Concert scene type at a concert…

Scene = Darken

The Darken scene type is called for here to help with the overexposure. While it doesn’t completely fix the problem, it certainly helps.

Scene = Darken

The Darken filter used again to good effect.

Scene = Darken, followed by Special Filter = HDR @ 20%

This example shows a powerful feature of Camera+    the ability to layer an Effect on top of a Scene type. You can only use one of each, and you can’t put a scene on top of another scene (or an effect on top of an effect) – but the potential of changes has now multipled enormously. Here, the original scene was overexposed. A combination of the Darken scene type, followed by the HDR filter at 30% intensity made all the difference.

Scene = Flash

This shows a typical challenging scene to capture correctly – a dark interior looking out to a brightly lit exterior. In the original exposure you can see that the camera exposed for the outdoor portion, leaving the intererior very dark. The first attempt to rectify this is using the Flash scene type. While this helped the bookcases in the hall, the exterior is now totally blown out, and the right foreground is still too dark.

Scene = Night

Here is the result of using the Night scene type. Better detail in both the hallway as well as the right foreground – and the exterior is now visible, even though still a bit overexposed.

Special Filter = HDR

This version uses the HDR effect filter – giving the best overall exposure between the outside, the bookcase and the foreground. Ideally, I would follow up with another app and raise the black levels a bit to bring out more detail in the shadows in the foreground and near part of the hall.

Scene = Flash

A night-blooming cactus photographed before sunrise – it’s a bit underexposed. Using the Flash scene type brings out the plant well, but the white flowers are now too hot.

Scene = Night

The Night scene type provides a better result, with good balance between the flowers, plant and trees behind.

Special Filter = HDR

Using the HDR filter to attempt to improve the foreground illumination of this shot. It helps… but the typical style of this tone-mapping filter oversaturates the reds in the wood, and the foreground is still a bit dark.

Scene = Flash

And here’s another attempt, using the Flash scene type. A different set of side effects.. the sunlight on the wall is now overexposed, and the foreground is still not ideally lit. Camera+ can’t fix everything… (in this case, using a different app – PhotoForge2 – which has a powerful tool “Shadows & Highlights” did a better job. We’ll see that when we get around to discussing that app).

Scene = Flash

Here’s a good use for the Flash scene. The original is very dark, the filtered version really does look like a flash had been used.

Scene = Flash

And here’s one that didn’t work so well. The Flash filter didn’t do what a real flash would have done: illuminated the interior without making any difference at all in the exterior lighting. Here, the opposite took place: the sunset sky is blown out, yet the interior isn’t helped out any at all.

Scene = Flash

Flash scene used on shot out airplane window, takeoff from London in late twilight. Doesn’t work for me…

Scene = Night

This time, Night was used. Less dramatic – personally I prefer the original. But it’s a good example to show how the different filters operate.

Scene = Food

Ok, just had to try food with Food (scene type)… You can see the filter at work:  whites are warmed up with more red; the potatoes now look almost like little sausages, contrast is increased. I would really like it if the Intensity sliders would be added to the Scene types as well as the Effects… here a better result would be found with about 40% of this filter dialed in, I believe…

Special Filter = HDR

Main street in Montagu, a little town in South Africa. The HDR filter shows how to help resolve a high contrast scene. I didn’t redo this one, but I would have had a more natural look if I had dialed back the intensity of the HDR filter to about 50%.

Scene = Scenery

The Scenery filter applied to an outdoor scene.I find this too contrasty, and even the sky looks a bit oversaturated.

Scene = Clarity

Here is Clarity applied to the same image. Shadow detail much improved (except right under nearest arch). However the right side of the image looks a bit ‘post-cardy’ (flat and washed out).

Special Filter = HDR @ 35%

HDR filter applied at 35%. A different set of ‘almost but not quite’ issues… Arches in shadows are too blue, the sunlit portions are blown out, and the sky is too saturated. The trees on the right are a big improvement over the previous version (Clarity) however. Sometimes you really do need Photoshop….

Scene = Clarity

This is a tough shot:  extreme brightness differences – my estimate is over 14 stops of exposure – way more than the iPhone camera can handle. So it’s really a matter of how best to interpret a scene that will inevitably have both white and black clipping. I used Clarity on this version – didn’t help out the highlights at all, but did add some detail in the shadows, as well as a bit of punch to her pants.

Special Filter = HDR @ 50%

The HDR effect was used here at 50% intensity. This brough a bit more control to at least the edges of the highlights, and still opened up the shadows. Note the difference in the shaded carpet at lower left of the image from this version to the previous one (done with Clarity). I actually prefer this version – the Clarity one seems a bit too much. Overall, I think this does a better job of this particular scene.

Scene = Night

Showing the use of the Night scene type at the last few minutes of twilight. As is often the case, I prefer the original shot, but wanted to demonstrate the capabilities of this scene type. Technically it did a great job – it just didn’t tell the story in the same way as the original.

Scene = Night

Now this scene is an excellent example of what the Night filter can do in the right circumstance. Almost full dark, only illumination was from store windows, streetlights and headlights.

Scene = Night

The Night scene type bringing out enough detail to make the shot.

Scene = Night

One more Night shot – again, a very good use of this scene type.

Scene = Night, followed by Special Filter = HDR @ 33%

This is an example of ‘stacking’ two corrections on top of each other to fix a shot that really needed help. You don’t always have to use the Night scene type at night… Here, due to both underexposure and backlight, the Night filter was applied first, then HDR effect at 33% intensity on top of that. It’s not a perfect result but it definitely shows you what can be done with these tools.

Scene = Portrait

The Portrait scene type applied. The contrast is too much, and the red saturation makes her skin tones look like a lobster.

Color Filter = So Emo

A very different effect, using the So Emo filter.

Scene = Clarity

Just to show what Clarity does in this instance. Again, not the best choice – the background gets too busy, and her face suffers…

Scene = Portrait

Here is Portrait applied to, well, a portrait type shot. But once again the high contrast of this filter works against the best result:  blown out highlights, skin tones too bright.

Scene = Shade

Sometimes you use filters in not-obvious ways:  the Shade scene type was applied here, and from that we got a slight improvement in background brightness, without driving her top into clipping. You can now see some definition between her hair and the background, and the slight warmth added does not detract from the image.

Scene = Sunset

The Sunset filter applied at sunset… I think this is too much. The extra contrast killed the detail in the trees at right center, and the red roof is artificially saturated now.

Scene = Scenery

The Scenery filter applied at sunset. Looks a bit different than the Sunset filter, above, but has many of the same issues when used on this scene: loss of detail in the shadows, too much red saturation.

Scene = Scenery

The Scenery filter at sunset. If this scene type could be ratcheted down with a slider, like is possible with the Effects, then this shot could be enhanced nicely. The original is just a tad flat looking, but the full Monty of the Scenery filter is way over the top. I would love to see what 20% of this effect would do.

Scene = Shade

This shows the Shade scene type doing exactly what it is supposed to: warm up the skin tones, add a bit of brightness. Altogether a less forlorn look…

Scene = Clarity

The same shot with Clarity applied. Much punchier – while I like the detail it’s almost too much. Again, Camera+ engineers, please bring us intensity sliders for scene types!

Scene = Sunset

Now here’s a use for the Sunset scene type at last. While it may not be the best storytelling tool for this particular shot, it shows the nice punch and improvement in detail and saturation this filter can provide – once the original image is basically soft enough to take the sometimes overpowering influence of this scene type.

Scene = Sunset

Trying the Sunset scene type once again. If I could use this at half strength it would actually make this shot a bit more colorful – but in its current incarnation the saturation is too much.

Scene = Sunset

Last Sunset for this post. I promise… but just to prove that never say never… here is a sunset where applying Sunset certainly helps the sky and water. I would like the sign not as saturated, and the increased constrast cost us the few remaining details hidden in the market building at the bottom of the frame.

Scene = Text

This is an example of the Text scene type. Ultra high contrast – really just for what it says (or other special effect you want to create using an almost vertical gamma curve!)

Digital Zoom

Now.. one last thing before the end of this post: a very short dicussion of Digital Zoom. I have ignored this topic up until now. But it’s really really important in iPhonography (actually this affects all cellphone cameras, as well as many small inexpensive digital cameras). ‘Real’ cameras (i.e. all DSLRs and many mid-priced and up digital cameras use Optical Zoom (or as in some consumer type digital cameras, both optical and digital zoom are offered). The difference is that with optical zoom, the lens elements physically move (i.e. a real zoom lens), changing both the magnification and the field of view that is projected onto the film or digital sensor. The so-called ‘Digital Zoom’ technique is a result of physical lenses that cannot “zoom”. Cellphone lenses are too small to adjust their focal length like a DSLR lens does. Also, the optical complexity of a zoom lens is far greater than that of a prime lens (fixed focal length) – and the light-gathering power of a zoom lens is always significantly less than that of a prime lens. (You can get relatively fast zoom lenses for DSLRs… as long as you have the budget of a small country…)

What the “digital zoom” technique is actually doing is cropping the image on the CMOS sensor (using only a small portion of the available pixels), then digitally magnifying that area back out to the original size of the sensor (in pixels). For example, the iPhone sensor is 3264×2448. If one were to crop down to 50% of the original area covered by the lens (to 1632×1224) the lens would now only be covering 1/4 of the original area. Do the math:  3264×2448 is 8megapixels; 1632×1224 is now only 2megapixels. What you do get for this is an apparent ‘zoom’ – or greater percieved magnification, due to the new ‘sensor size’ and the fact that the original focal lenght of the lens has not changed. The original 35mm equivalent focal length of the iPhone camera system is 32mm – by ‘cropping/zooming’ as described, the new focal length is now 4x greater, or 128mm (in 35mm equivalent terms). However – and this is a HUGE however – you pay a large price for this: resolution and noise. You now only have a 2megapixel sensor… not the supersharp 8megapixel sensor that you started with. This is like stepping all the way back to the iPhone 3 – which had 2MP resolution. Wow! In addition, these 2megapixels are now “zoomed” back to fill the full size of the original 8MP sensor (in memory), essentially this means that each original pixel of the taking sensor now covers 4 pixels in the newly formed zoomed image. This means that any noise in the original pixel is magnified by 4 times… So the bottom line is that digital zoom ALWAYS makes noisy, low resolution images.

Now.. just like in any good sales effort, you will hear grand ‘snake oil’ stories of how good this camera or that camera does at ‘digital zoom’ – and that it’s “just as good” as optical zoom. BS. Period. You can’t change the laws of physics…. What is possible (and bear in mind that this is a really small band-aid on a big owie…) is to use some really sophisticated noise reduction and image processing algorithms to try to make this pot of beans look like filet again… and most hardware and software camera manufacturers try at some level. Yes, if such attempts succeed, then you are a LITTLE better off than you were before. Not much. So what’s the answer. Don’t use digital zoom. Just say no. Unless you can accept the consequences (noisy, low resolution images). We’ll discuss this further in the last part of this series on Tips & Techniques for iPhonography, but for now you will see why I don’t address it as a feature.

Ok, that’s it. Really. Hope you have a bit more info now about this very useful app. Many of my upcoming posts on the rest of the sofware tools for the iPhone will not be nearly as detailed, but this was an opportunity to discuss many topics that are germane to most photography apps; offer a bit of a guide to a very popular and useful app that currently publishes no manual or even a help screen, and to demonstrate the thought process involved in working with filters, lighting and so on.

Many thanks for your attention.

iPhone4S – Section 4a: Camera app

March 14, 2012 · by parasam

Camera   The original iPhone photo app. Pretty simple – Use camera icon button to take picture, or use Volume Up (+) on side of phone. Option buttons on top of screen:

  • Flash: On/Auto/Off
  • Options:  Grid – On/Off;  HDR – On/Off
  • Rear-facing/Front-facing camera selector

Features/Buttons on bottom of screen:

  • Last shot preview thumbnail
  • Shutter release button
  • Still/Video selector

Blue box is area where both exposure and focus are measured. Option buttons across top of screen.

When "Options" is selected, you can choose to display a grid overlay on the screen for aid in composition; turn HDR feature on or off.

When 'video' mode is selected, the options change, and the shutter button changes to a 'record' button. Press to start recording, press again to stop.

iPhone4S – Section 4: Software

March 13, 2012 · by parasam

This section of the series of posts on the iPhone4S camera system will address the all-important aspect of software – the glue that connects the hardware we discussed in the last section with the human operator. Without software, the camera would have little function. Our discussion will be divided into three parts:  Overview; the iOS camera subsystem of the Operating System; and the actual applications (apps) that users normally interact through to take and process images.

As the audience of this post will likely cover a wide range of knowledge, I will try to not assume too much – and yet also attempt not to bore those of you who likely know far more than I do about writing software and getting it to behave in a somewhat consistent fashion…

Overview

The iPhone, surprise-surprise – is a computer. A full-fledged computer, just like what sits on your desk (or your lap). It has a CPU (brain), memory, graphics controller, keyboard, touch surface (i.e. mouse), network card (WiFi & Bluetooth), a sound card and many other chips and circuits. It even has things most desktops and laptops don’t have:  a GPS radio for location services, an accelerometer (a really tiny gyroscope-like device that senses movement and position of the phone), a vibrating motor (to bzzzzzz at you when you get a phone call in a meeting) – and a camera. A rather cool, capable little camera. Which is rather the point of our discussion…

So… like any good computer, it needs an operating system – a basic set of instructions that allows the phone to make and receive calls, data to be written to and read from memory, information to be sent and retrieved via WiFi – and on and on. In the case of the iDevice crowd (iPod, iPhone, iPad) this is called iOS. It’s a specialized, somewhat scaled down version of the full-blown OS that runs on a Mac. (Actually it’s quite different in the details, but the concept is exactly the same). The important part of all this for our discussion is that a number of basic functions that affect camera operation are baked into the operating system. All an app has to do is interact via software with these command structures in the OS, present the variable to the user in a friendly manner (like turn the flash on or off), and most importantly, take the image data (i.e the photograph) and allow the user to save it or modify it, based on the capability of the app in question.

The basic parameters that are available to the developer of an app are the same for everyone. It’s an equal playing field. Every app developer has exactly the same toolset, the same available parameters from the OS, and the same hardware. It’s up to the cleverness of the development team to achieve either brilliance or mediocrity.

The Core OS functions – iOS Camera subsystem

The following is a very brief introduction to some of the basic functions that the OS exposes to any app developer – which forms the basis for what an app can and cannot do. This is not an attempt to show anyone how to program a camera app for the iPhone! Rather, a small glimpse into some of the constraints that are put on ALL app developers – the only connection any app has with the actual hardware is through the iOS software interface – also known as the API (Application Programming Interface). For instance, Apple passes on to the developers through the API only 3 focus modes. That’s it. So you will start to see certain similarities between all camera apps, as they all have common roots.

There are many differences, due to the way a given developer uses the functions of the camera, the human interface, the graphical design, the accuracy and speed of computations in the app, etc. It’s a wide open field, even if everyone starts from the same place.

In addition, the feature sets made available through the iOS API change with each hardware model, and can (and do!) change with upgrades of the iOS. Of course, each time Apple changes the underlying API, each app developer is likely to need to update their software as well. So then you’ll get the little red number on your App Store icon, telling you it’s time to upgrade your app – again.

The capabilities of the two cameras (front-facing and rear-facing) are markedly different. In fact, all of the discussion in this series has dealt only with the rear-facing camera. That will continue to be the case, since the front-facing camera is of very low resolution, intended pretty much just to support FaceTime and other video calling apps.

Basic iOS structure

The iOS is like an onion, layers built upon layers. At the center of the universe… is the Core. The most basic is the Core OS. Built on top of this are additional Core Layers: Services, Data, Foundation, Graphics, Audio, Video, Motion, Media, Location, Text, Image, Bluetooth – you get the idea…

Wrapped around these “apple cores” are Layers, Frameworks and Kits. These Apple-provided structures further simplify the work of the developer, provide a common and well tuned user interface, and expand the basic functionality of the core systems. Some examples are:  Media Layer (including MediaPlayer, MessageUI, etc.); the AddressBook Framework; the Game Kit; and so on.

Our concern here will be only with a few structures – the whole reason for bringing this up is to allow you, the user, to understand what parameters on the camera and imaging systems can be changed and what can’t.

Focus Modes

There are three focus modes:

  • AVCaptureFocusModeLocked: the focal area is fixed.

This is useful when you want to allow the user to compose a scene then lock the focus.

  • AVCaptureFocusModeAutoFocus: the camera does a single scan focus then reverts to locked.

This is suitable for a situation where you want to select a particular item on which to focus and then maintain focus on that item even if it is not the center of the scene.

  • AVCaptureFocusModeContinuousAutoFocus: the camera continuously auto-focuses as needed.

Exposure Modes

There are two exposure modes:

  • AVCaptureExposureModeLocked: the exposure mode is fixed.
  • AVCaptureExposureModeAutoExpose: the camera continuously changes the exposure level as needed.

Flash Modes

There are three flash modes:

  • AVCaptureFlashModeOff: the flash will never fire.
  • AVCaptureFlashModeOn: the flash will always fire.
  • AVCaptureFlashModeAuto: the flash will fire if needed.

Torch Mode

Torch mode is where a camera uses the flash continuously at a low power to illuminate a video capture. There are three torch modes:

  •    AVCaptureTorchModeOff: the torch is always off.
  •    AVCaptureTorchModeOn: the torch is always on.
  •    AVCaptureTorchModeAuto: the torch is switched on and off as needed.

White Balance Mode

There are two white balance modes:

  •    AVCaptureWhiteBalanceModeLocked: the white balance mode is fixed.
  •    AVCaptureWhiteBalanceModeContinuousAutoWhiteBalance: the camera continuously changes the white balance as needed.

You can see from the above examples that many of the features of the camera apps you use today inherit these basic structures from the underlying CoreImage API. There are obviously many, many more parameters that are available for control by a developer team – depending on whether you are doing basic image capture, video capture, audio playback, modifying images with built-in filter, etc. etc.

While we are on the subject of core functionality exposed by Apple, let’s discuss camera resolution.

Yes, I know we have heard a million times already that the iPhone4S has an 8MP maximum resolution (3264×2448). But there ARE other resolutions available. Sometimes you don’t want or need the full resolution – particularly if the photo function is only a portion of your app (ID, inventory control, etc.) – or even as a photographer you want more memory capacity and for the purpose at hand a lower resolution image is acceptable.

It’s almost impossible to find this data, even on Apple’s website. Very few apps give access to different resolutions, and the ones that do don’t give numbers – it’s ‘shirt sizes’ [S-M-L]. Deep in the programming guidelines for CoreImage I found a parameter AVCaptureStillIMageOutput that allows ‘presetting the session’ to one of the values below:

PresetNameStill           PresetResolutionStill

Photo                              3264×2448

High                                1920×1080

Med                                 640×480

Lo                                   192×144

PresetNameVideo         PresetResolutionVideo

1080P                              1920×1080

720P                                1280×720

480P                                640×480

I then found one of the very few apps that support ALL of these resolutions (almost DSLR) and shot test stills and video at each resolution to verify. Everything matched the above settings EXCEPT for the “Lo” preset in Still image capture. The output frame measured 640×480, the same as “Med” – however the image quality was much lower. I believe that the actual image IS captured at 192×144, but then is scaled up to 640×480 – why I am not sure, but it is apparent that the Lo image is of far lower quality than Med. The image size was lower for the Lo quality image – but not enough that I would ever use it. On the tests I shot, Lo = 86kB, Med = 91kB. The very small difference in size is not worth the big drop in quality.

So… now you know. You may never have need of this, or not have an app that supports it – but if you do require the ability to shoot thousands of images and have them all fit in your phone, now you know how.

There are two other important aspects of image capture that are set by the OS and not changeable by any app:  color space and image compression format. These are fixed, but different, for still images and video footage. The color space (which for the uninitiated is essentially the gamut – or range of colors – that can be reproduced by a color imaging system) is set to sRGB. This is a common and standard setting for many digital cameras, whether full sized DSLR or cellphones.

It’s beyond the scope of this post to get into color space, but I personally will be overjoyed when the relatively limited gamut of sRGB is put to rest… however, it is appropriate for the iPhone and other cellphone camera systems due to the limitations of the small sensors.

The image compression format used by the iPhone (all models) is JPEG, producing the well-known .jpg file format. Additional comments on this format, and potential artifacts, were discussed in the last post. Since there is nothing one can do about this, no further discussion at this time.

In the video world, things are a little different. We actually have to be aware of audio as well – we get stereo audio along with the video, so we have two different compression formats to consider (audio and video), as well as the wrapper format (think of this as the envelope that contains the audio and video track together in sync).

One note on audio:  if you use a stereo external microphone, you can record stereo audio along with the video shot by the iPhone4S. This requires an external device which connects via the 30-pin docking connector. You will get far superior results – but of course it’s not as convenient. Video recordings made with the on-board microphone (same one you use to speak into the phone) are mono only.

The parameters of the video and audio streams are detailed below: (this example is for the full 1080P resolution)

General

Format : MPEG-4
Format profile : QuickTime
Codec ID : qt
Overall bit rate : 22.9 Mbps

Video

ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : Baseline@L4.1
Format settings, CABAC : No
Format settings, ReFrames : 1 frame
Codec ID : avc1
Codec ID/Info : Advanced Video Coding
Bit rate : 22.4 Mbps
Width : 1 920 pixels
Height : 1 080 pixels
Display aspect ratio : 16:9
Rotation : 90°
Frame rate mode : Variable
Frame rate : 29.500 fps
Minimum frame rate : 15.000 fps
Maximum frame rate : 30.000 fps
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.367
Title : Core Media Video
Color primaries : BT.709-5, BT.1361, IEC 61966-2-4, SMPTE RP177
Transfer characteristics : BT.709-5, BT.1361
Matrix coefficients : BT.709-5, BT.1361, IEC 61966-2-4 709, SMPTE RP177

Audio

ID : 2
Format : AAC
Format/Info : Advanced Audio Codec
Format profile : LC
Codec ID : 40
Bit rate mode : Constant
Bit rate : 64.0 Kbps
Channel(s) : 1 channel
Channel positions : Front: C
Sampling rate : 44.1 KHz
Compression mode : Lossy
Title : Core Media Audio

The highlights of the video/audio stream format are:

  • H.264 (MPEG-4) video compression, Baseline Profile @ Level 4.1, 22Mb/s
  • QuickTime wrapper (.mov)
  • AAC-LC audio compression, 44.1kHz, 64kb/s

The color space for the video is the standard adopted for HD television, Rec709. Importantly, this means that videos shot on the iPhone will look correct when played out on an HDTV.

This particular sample video I shot for this exercise was recorded at just under 30 frames per second (fps), the video camera supports a range of 15-30fps, controlled by the application.

Software Applications for Still & Video Imaging on the iPhone4S

The following part of the discussion will cover a few of the apps that I use on the iPhone4S. These are just what I have come across and find useful – this is not even close to all the apps available for the iPhone for imaging. I obtained all of the apps via normal retail Apple App Store – I have no relationship with any of the vendors – they are unaware of this article (well, at least until it’s published…)

I am not a professional reviewer, and take no stance as to absolute objectivity – I do always try to be accurate in my observations, but reserve the right to have favorites! The purpose in this section is really to give examples of how a few representative apps manage to expose the hardware and underlying iOS software to the user, showing the differences in design and functionality.

These apps are mostly ‘purpose-built’ for photography – as opposed to some other apps that have a different overall purpose but contain imaging capabilities as part of the overall feature set. One example (that I have included below) is EasyRelease, an app for obtaining a ‘model release’ [legal approval from the subject to use his/her likeness for commercial purposes]. This app allows taking a picture with the iPhone/iPad for identification purposes – so has some very basic image capture abilities – it’s not a true ‘photo app’.

BTW, this entire post has been focused on only the iPhone camera, not the iPad (both 2nd & 3rd generation iPads contain cameras) – I personally don’t think a tablet is an ideal imaging device – it’s more like a handy accessory if you have your tablet out and need to take a quick snap – than a camera. Evidently Apple feels this way as well, since the camera hardware in the iPads have always lagged significantly behind that of the iPhone. However, most photo apps will work on both the iPad as well as the iPhone (even on the 1st generation model – with no camera), since many of the apps support working with photos from the Camera Roll (library) as well as directly from the camera.

I frequently work this way – shoot on iPhone, transfer to iPad for easier editing (better for tired eyes and big fingers…), then store or share. I won’t get into the workflows of moving images around – it’s not anywhere near as easy as it should be, even with iCloud – but it’s certainly possible and often worth the effort.

Here is the list of apps that will be covered. For quick reference I have listed them all below with a simple description, a more detailed set of discussions on each app follows.

[Note:  due to the level of detail, including many screenshots and photo examples used for the discussion of each app, I have separated the detailed discussions into separate posts – one for each app. This allows the reader to only select the app(s) they may be interested in, as well as keep the overall size of an individual post to a reasonable size. This is important for mobile readers…]

Still Imaging

Each of the app names (except for original Camera) is a link that will take you to the corresponding page in the App Store.

Camera  The original photo app included on every iPhone. Basic but intuitive – and of course the biggest plus is the ability to fast-launch this without logging in to the home page first. For streetphotography (my genre) this a big feature.

Camera+  I use this as much for editing as shooting, biggest advantage over native iPhone camera app is you can set different part of frame for exposure and focus. The info covers the just-released version 3.0

Camera Plus Pro  This is similar to the above app (Camera+) – some additional features, not the least of which it shoots video as well as still images. Although made by a different company, it has many similar features, filters, etc. It allows for some additional editing functions and features ‘live filters’ – where you can add the filter before you start shooting, instead of as a post-production workflow in Camera+. However, there are tradeoffs (compression ratio, shooting speed, etc.)  Compare the apps carefully – as always, know your tools…  {NOTE: There are two different apps with very similar names: Camera+, made by TapTapTap with the help of pixel wizard Lisa Bettany; and Camera Plus, made by Global Delight Technologies – who also make Camera Plus Pro – the app under discussion here. Camera+ costs $0.99 at the time of this post; Camera Plus is free; Camera Plus Pro is $1.99 — are you confused yet? I was… to the point where I felt I needed to clarify this situation of unfortunately very similar brand names for somewhat similar apps – but there are indeed differences. I’m going to be as objective in my observations as possible. I am not reviewing Camera Plus, as I don’t use it. Don’t infer anything from that – this whole blog is about what I know about what I personally use. I will be as scientific and accurate as possible once I write about a topic, but it’s just personal preference as to what I use}

almost DSLR is the closest thing to fully manual control of iPhone camera you can get. Takes some training, but is very powerful once you get the hang of it.

ProHDR I use this a lot for HDR photography. Pic below was taken with this. It’s unretouched! That’s how it came out of the camera…

Big Lens This allows you to manually ‘blur’ background to simulate shallow depth of field. Quite useful since 30mm focal length lens (35mm equivalent) puts almost everything in focus.

Squareready  If you use Instagram then you know you need to upload in square format. Here’s the best way to do that.

PhotoForge2  Powerful editing app. Basically Photoshop on the iPhone.

Snapseed  Another very good editing app. I use this for straightening pix, as well as ability to tweak small areas of picture differently. On some iPhone snaps I have changed 9 different areas of picture with things like saturation, contrast, brightness, etc.

TrueDoF  This one calculates true depth-of-field for a given lens, sensor size, etc. I use this when shooting DSLR to plan my range of focus once I know my shooting distance.

OptimumCS-Pro  This is sort of inverse of the above app – here you enter the depth of field you want, then OCSP tells you the shooting distance and aperture you need for that.

Iris Photo Suite  A powerful editing app, particularly in color balance, changing histograms, etc. Can work with layers like Photoshop, perform noise reduction, etc.

Filterstorm  I use this app to add visible watermarks to images, as well as many other editing functions. Works with layers, masks, variable brushes for effects, etc.

Genius Scan+  While this app was intended for (and I use it for this as well) scanning documents with the camera to pdf, I found that it works really well to straighten photos… like when you are shooting architectural and have unavoidable keystoning distortion… Just be sure to pull back and give yourself some surround on your subject, as the perspective cropping technique that is used to straighten costs you some of your frame…

Juxtaposer  This app lets you layer two different photos onto each other, with very controllable blending.

Frame X Frame  Camera app, used for stop motion video production as well as general photography.

Phonto  One of the best apps for adding titles and text to shots.

SkipBleach  This mimics the effect of skipping (or reducing) the bleach step in photochemical film processing. It’s what gives that high contrast, faded and harsh ‘look’.

Monochromia  You probably know that getting a good B&W shot out of a color original is not as simple as just desaturating.. here’s the best iPhone app for that.

MagicShutter  This app is for time exposures on iPhone, also ‘light painting’ techniques.

Easy Release  Professional model release. Really, really good – I use it on iPad and have never gone back to paper. Full contractual terms & conditions, you can customize with your additional wording, logo, etc. – a relatively expensive app ($10) but totally worth it in terms of convenience and time saved if you need this function.

Photoshop Express  This is actually a bit disappointing for a $5 app, others above do more for less – except the noise reduction (a new feature) is worth it for that alone. It’s really, really good.

Motion Imaging

Movie*Slate  A very good slate app.

Storyboard Composer  Excellent app for building storyboards from shot or library photos, adding actors, camera motion, script, etc. Powerful.

Splice  Unbelievable – a full video editor for the iPhone/iPad. Yes, you can: drop movies and stills on a timeline, add multiple sound tracks and mix them, work in full HD, has loads of video and audio efx, add transitions, burn in titles, resize, crop, etc. etc. Now that doesn’t mean that I would choose to edit my next feature on a phone…

iTC Calc  The ultimate time code app for iDevices. I use on both iPad and iPhone.

FilmiC Pro  Serious movie camera app for iPhone. Select shooting mode, resolution, 26 frame rates, in-camera slating, colorbars, multiple bitrates for each resolution, etc. etc.

Camera+ Pro  This app is listed under both sections, as it has so many features for both still and motion photography. The video capture/edit portion even has numerous filters that can be used during capture.

Camcorder Pro  simple but powerful HD camera app. Anti-shake and other features.

This concludes this post on the iPhone4S camera software. Please check out the individual posts following for each app mentioned above. I will be posting each app discussion as I complete it, so it may be a few days before all the app posts are uploaded. Please remember these discussions on the apps are merely my observations on their behavior – they are not intended to be a full tutorial, operations manual or other such guide. However, in many cases, the app publisher offers little or no extra information, so I believe the data provided will be useful.

iPhone4S – Section 3: Specifications & Hardware

March 11, 2012 · by parasam

This chapter of my series on the iPhone4S attempts to share what I have discovered on the actual hardware device – restricted to the camera in the iPhone. While this is specific to the iPhone, this is also representative of most high quality cellphone cameras.

First, a few notes on how I went about this, and some acknowledgements for those that discovered these bits first. All of the info I am sharing in this post was derived from the public internet. Where feasible I have tried to make direct acknowledgment of the source, but the formatting of this blog doesn’t always allow that without confusion (footnotes not supported, etc.) so I will insert a short list of sources just below. Although this info was pulled from the web, it has taken a LOT of research – it is not easy to find, and often the useful bits are buried in long sometimes boring epistles on the entire iPhone – I want to focus just on the camera.

Apple, more than most manufacturers, is an incredibly secretive company. They put highly onerous stipulations on all their vendors – in terms of saying anything about anything at all that concerns work they do for Apple. Apple publishes only the most vague of specifications, and often that is not enough for a photographer that wants to get the most from his or her hardware. This policy will likely never change, so the continued efforts of myself and others will be required to unearth the useful bits about the device so we can use it to its fullest potential.

Here are some of the sources/people that published information on the iPhone4S that were used as sources for this article:

engadget.com

apple.com

iFixit.com

chipworks.com

arstechnica.com

sony.com

omnivision.com

jawsnap.net

whatdigitalcamera.com – Nigel Atherton

bcove.me

wired.com

geekbench.com

iprolens.com

eoshd.com

macrumors.com

forbes.com

image-sensors-world.blogspot.com

opco.bluematrix.com

oppenheimer.com

barons.com

motleyfool.com

isuppli.com

anandtech.com

teledyne.com

thephoblographer.com

popphoto.com

dvxuser.com – Barry Green

campl.us – Jonathan

Often the only way to finally arrive at a somewhat accurate idea of what made the iPhone tick was to study the ordering patterns of Chinese supply companies – using publicly available financial statements; review observations and suppositions from a large number of commentators and look for sufficient agreement; find labs that tore the phones apart and reverse-engineered them; and often using my decades of experience as a scientist and photographer to intuit the likelihood of a particular way of doing things. It all started with a bit of curiosity on my part – I had no idea what a lengthy treasure hunt this would turn out to be. The research for this chapter has taken several months (after all, I have a day job…) – and then some effort to weed through all the data and assemble what I believe to be as accurate an explanation of what goes on inside this little device as possible.

One important thing to remember:  Apple is in the habit of sourcing parts for their phone from two or more suppliers – a generally accepted business practice, since a single-source supplier could be a problem if that company had either financial or physical difficulties in fulfillment. This means that a description, photos, etc. of one vendor’s parts may not hold true for all iPhone4S models or inventory – but the general principles will be accurate.

Specifications

This post will be presented in three parts:  the hardware specs first, followed by details of the construction of the iPhone camera system (with photos of the insides of the phone/camera), then some examples of photos taken with various models of the iPhone and some DSLR cameras for comparison – this to show the relative capability of the iPhone hardware. The software apps that are the other half of the overall imaging system will be discussed in the next post.

iPhone4S detailed specs

Camera Sensor                 Omnivision  OV8830 or Sony IMX105

Sensor Type                       CMOS-BSI  (Complementary Metal Oxide Semiconductor – Backside Illumination)

Sensor Size                         1/3.2″ (4.54 x 3.42 mm)

Pixel Size                             1.4 µm

Optical Elements              5 plastic lens elements

Focal Length                     4.28 mm

Equivalent Focal Length (ref to 35mm system) – Still        32 mm

Equivalent Focal Length (ref to 35mm system) – Video   42 mm

Aperture                            f 2.4

Angle of View – Still           62°

Aspect Ratio – Still           4:3

Angle of View – Video      46°

Aspect Ratio – Video       16:9

Shutter Speed – Still        1/15 sec – 1/2000 sec

ISO Rating                       64 – 800

Sensor Resolution – Still              3264 x 2448 (8 MP)

Sensor Resolution – Motion        1920 x 1080  (1080P HD)

External Size of Camera System Module                8.5 mm W x 8.5 mm L x 6 mm D

Features:

  • Video Image Stabilization
  • Temporal Noise Reduction
  • Hybrid IR Filter
  • Improved Automatic White Balance (AWB)
  • Improved light sensitivity
  • Macro focus down to 3”
  • Improved Color Accuracy
  • Improved Color Uniformity

Discussion on Specifications

iPhone4S Camera Assembly

Sensor – “Improved Light Sensitivity”

We’ll start with some basics on the heart of the camera assembly, the sensor. There are two types of solid-state devices that are used to image light into a set of electrical signals that can eventually be computed into an image file:  CCD (Charge Coupled Device) and CMOS (Complementary Metal Oxied Semiconductor). CCD is an older technology, but produces superior images due to the way it’s constructed. However, these positive characteristics come at the cost of more outboard circuitry, higher power consumption, and higher cost. These CCD arrays are used almost exclusively in mid-to-high-end DSLR cameras. CMOS offers lower cost, much lower power consumption and requires fewer off-sensor electronics. For these reasons all cellphone cameras, including the iPhone, use CMOS sensors.

For those slightly more technically inclined, here is a good paragraph from Teledyne.com that sums up the differences:

Both types of imagers convert light into electric charge and process it into electronic signals. In a CCD sensor, every pixel’s charge is transferred through a very limited number of output nodes (often just one) to be converted to voltage, buffered, and sent off-chip as an analog signal. All of the pixel can be devoted to light capture, and the output’s uniformity (a key factor in image quality) is high. In a CMOS sensor, each pixel has its own charge-to-voltage conversion, and the sensor often also includes amplifiers, noise-correction, and digitization circuits, so that the chip outputs digital bits. These other functions increase the design complexity and reduce the area available for light capture. With each pixel doing its own conversion, uniformity is lower. But the chip can be built to require less off-chip circuitry for basic operation.

Apple claims “73% more light” for the sensor used in the iPhone4S. Whatever that means… 73% of what?? Anyway, here is what, after some web-diving, I think is meant:  73% more light is converted to electricity as compared to the sensor used in the iPhone4. The reason is an improvement in the design of the CMOS sensor. The new device uses a technology called “Back Side Illumination”, or BSI. To understand this we must briefly discuss the way a CMOS sensor is built.

One of the big differences between CCD and CMOS sensors is that the CMOS chip has a lot of electr