iPhone 4S camera: why it won't replace your compact

Commentary This time last year, when the iPhone 4 was announced, we published a piece looking at the iPhone 4's camera and its potential to change the imaging market.

One year on, we have the iPhone 4S, the same external case with a new camera (amongst many other features) inside. What was most interesting about the announcement, spare the disappointment from many that the phone itself wasn't the much-longed-for iPhone 5, was the bold claim made by Phil Schiller: "for many customers, the iPhone 4S will be the best camera ... and video camera they've ever had," he said. So, does the 4S have the chops to be the best camera for these people?

Lots of (unique) features?

The camera on the iPhone 4S has several new features, including an f/2.4 lens, extra lens element for increased sharpness, 8-megapixel backlit CMOS sensor and full HD video recording at 1080p. While new for the iPhone, it's certainly not anything new for the world of compact cameras — many of which regularly push the boundaries in terms of lenses with wide maximum apertures, and can easily record 1080p video in an overall package smaller than the 4S. These features aren't particularly new for mobiles, either, come to think of it. Remember the Nokia N8 and the Samsung Galaxy S II, anyone?

The real killer feature that the iPhone's camera misses out on is optical zoom — one of the main reasons that someone would choose a compact rather than a phone for taking photos. An optical zoom would make any phone much more cumbersome, but a high zoom rating is still a "must have" feature on the list for many casual shooters when deciding on what camera to buy.

The size of the sensor also plays an important part in image quality. If the sensor size of the 4S's camera is physically the same as that found in the iPhone 4, simply giving it a higher megapixel count does not imply better quality images — in fact, it could lead to increased noise. The backlit CMOS sensor, while good for low-light photos, doesn't always hold up in ample light and daytime shots, something that exhibits itself in a range of compacts with backlit sensors. A small sensor also won't be able to deliver the shallow depth of field that many photographers expect from a lens at f/2.4. Then again, it's likely that the "many customers" disclaimer that Schiller included with his statement is meant to include everyday shooters who aren't particularly interested in aperture — just with the camera's ability to take a good shot in low light.

Also puzzling is Apple's hybrid infrared filter. The details, at this stage, are sparse, but as our colleagues at CNET point out, it is most likely a typical infrared filter that all cameras use, with better light transmission.

Image stabilisation for video recording is a welcome addition, but it's most likely to be digital stabilisation rather than optical, which we've seen produce some odd wobbling effects on still cameras that use this technology for video recording.

Performance

Here's the one area where mobile phones have the potential to outstrip their compact camera running mates: sheer speed. The dual A5 processors in the iPhone 4S look promising, particularly for photo processing and video recording. One of the perennial complaints from compact camera owners is the delay in processing and response times, particularly in regards to shutter lag. The iPhone 4S claims to start up and take its first shot within 1 second of launching the camera app, and has a 0.5 second shot-to-shot time, which is impressive, but certainly not class-leading (or camera killing).

What the iPhone does right

Though not unique to the iPhone 4S, its sharing and editing features are a cut above other cameras on the market. With barely a trickle of Wi-Fi cameras in Australia (and some memory card makers not committing to bringing Eye-Fi to the country), the 4S and other mobiles could win the war on connectivity. After all, who doesn't want to be able to share photos instantly with friends and family?

Even if the 4S and other mobiles with improved imaging capabilities fail to stir up the compact camera world, it should still be a wake-up call to many manufacturers who aren't seriously thinking about how consumers take and share photos.