Talking of the camera, it is very good. The sensor and optics are no better than the HTC One X or iPhone 4S but the results are at least as good if not better most of the time. The app offers plenty of options allowing you to tailor your shots according to shooting conditions, and the automatic settings tend to do a pretty good job.
However, the iPhone 4S tends to offer even more consistent automatic results (and has a better HDR mode) while the HTC One X offers by far the best interface, with a good balance of extra features and easy of use, but its pictures tend not to be quite so good when it comes to detail. Both the S3 and the One X also have markedly more powerful flashes than the iPhone, making them genuinely useful in dark situations.
We also noticed one oddity whereby tapping on the screen to pick your point of focus doesn't affect the overall metering of the image. So if you're trying to pick out a dark subject against a light background, for instance, the camera will often not get it right, exposing for the background and having a silhouette for a subject.
The powerful flash manages to completely illuminate our pitch black store room.
As an aside, all three of these phones really highlight how megapixels aren't the be all and end all as they all categorically beat the Sony Xperia S' 12 megapixel model.
Video recording is offered in up to 1080p resolution and again it's on par with much of the competition when it comes to detail. However, you can't toggle the flash during shooting and the autofocus did seem a bit erratic. There's also not a slow motion mode.