By Graham K. Rogers

One of the biggest drawbacks to the use of a smartphone camera over a DSLR, apart from the tut-tutting of would-be experts, is the size of the digital sensor. The number of megapixels is not the important factor, although many manufacturers of camera-capable devices cite this figure, which some consumers use as the sole guideline as to what a device can do.

Background

Anecdotally, a look at the crowds in any public place will show that more people are taking pictures with an iPhone, or an Android device, or even an iPad. There are always shrieks of horror at the idea of the iPad used as a camera, but like it or not, this (along with the iPhone) is what people use.

Apple was able to publicise use of iPhones for taking pictures with a one-minute advertisement that has a single line of dialogue: "Every day, more photos are taken with the iPhone than any other camera."

One of the attractions, apart from the ease of use, is the number of apps that are available for the iPhone (and iPad) that allow editing from a simple change of brightness up to complex filters, making it effortless for ordinary users to make changes to their images that a few years back might have needed a complex professional application on a PC or Mac.

How then does a camera app with a price tag of $1.99, that has no output adjustments, no filters - no editing capabilities at all - create any interest for users? There are two strong points about PureShot: its DSLR-like interface; and its output. For the first time, in my experience, I have an app that produces uncompressed images: neither JPEG, nor PNG, but a file type the developers call dRAW TIFF.

The developer, Michael Hardaker, whose excellent 6 x 6 and 6 x 7 apps are already favourites of mine, explains that "The term 'developed RAW' - dRAW - is used to describe a TIFF image that has had no in-app post-processing applied and, critically, no JPEG compression at any stage." This lack of compression is valuable in preserving an image (and its integrity) for post-processing and for further use.

iPhone Display

PureShot

Alongside the Menu button is a display (DISP) button that toggles between clear screen, grid only, grid plus data display and data display only (no grid). As an example of the thinking that went into this app, with the grid displayed, the center cross-hairs also act as a level indicator. Above the shutter button are AE and AF buttons that allow autoexposure and autofocus, or lock these.

There are nine (9) buttons at the bottom of the display. From left to right these are:

• Access to camera or photo album. When camera is active, a green arrow is displayed; when the album is being accessed, a camera icon is shown;
• Information (i) reveals a 30-page text about the app, which is also available as a PDF from the developer site;
• Self-timer - the default is 10 seconds but this may be changed in the menu from 1 - 60 seconds;
• Night Mode - on/off (this is to "enable longer exposure times (up to 1 second, depending on your iOS device), for greater low-light performance";
• White balance - locked/auto;
• Meter - spot/multi-zone;
• Flash - Off/Auto/Force On;
• Format allows the use of different display ratios: 1:1 (square), 3:2, 4:3 (default);
• The final button removes the bottom line of icons from the screen display on the iPhone and adjusts the side display to give a larger viewing area.

The full use of the buttons and the menu system means that the app and its output is highly configurable.

Output

As a comparison, my Nikon D7000 produces RAW images of 16.1 MP (4928 x 3264) with a file size of 18 - 19 MB. The image sensor of the Nikon is about 3 times the size of that in the iPhone (see Simon Crisp on Gizmag for an explanation of the differences).

When I used the square (1:1) aspect ratio, the image size was of course smaller at 2448 x 2448 (6 MP) and a file size of 17.15 MB. I also tried the app on the iPad. The display is full screen and almost identical to the display on the iPhone, although the larger screen area gives a cleaner display of controls. Images output from the iPad in PureShot in the dRAW TIFF format were 2592 x 2396 (5.0 MP) with a file size of 14.36 MB.

iPad Display

The unusually large size of the image, even from the iPhone, means that there is a lot more flexibility when using the app compared with output from other iOS software. The images were transferred directly to Aperture on the Mac using Photo Stream. I exported one or two test photographs to the desktop as TIFF 16-bit images.

I opened these in GraphicConverter and saw that an image was shown as 45.333" x 34" at 72 pixels/inch. I adjusted the size and resolution. With no apparent loss to the image, was able easily to produce an image 15" x 11.25" with a resolution of 210 pixels/inch: a higher value useful when printing pictures.

Comments

As a useful additional reference, you might find the ideas that Lexy Savvides covers in an article that appeared coincidentally a few hours after this first appeared.

Where PureShot positions itself is the gap between the SLR user and the snapper: someone who wants a slightly better output from the standard iPhone and who has a more mature approach to understanding the workings of a camera.

I mentioned above the apps 6 x 6 and 6 x 7 which were attempts to bring medium format output styles to the iPhone (my favourite of those is 6 x 7). PureShot is another bridge between the traditional and the modern. With an expected resolution increase for the next iPhone (perhaps to 12 MP) this is a good way to start experiencing better output from a smartphone camera.

Graham K. Rogers teaches at the Faculty of Engineering, Mahidol University in Thailand where he is also Assistant Dean. He wrote in the Bangkok Post, Database supplement on IT subjects. For the last seven years of Database he wrote a column on Apple and Macs.