"Look here upon this picture, and on this..."

I thought it might be interesting to look at how an iPhone JPEG file differs from a "raw" file produced by the Halide app. This is a fairly dramatic example, but serves to illustrate the issues.

iPhone JPEG

Halide raw

So, above, we have the JPEG as most smart phone users would see it. It's a nice enough picture: contrasty, saturated colours, blue sky, crisp details. A bit dark, maybe, but what's not to like? You could brighten it up a bit or not bother, then share it with your community of friends and lap up the "likes". Nice capture! Below it, we have a fairly extreme example of a "raw" DNG image, produced at the same time by Halide. Huh? WTF? Delete!! But wait...

The JPEG is eminently suitable for viewing on a screen, but is something of a travesty of the original scene, in two important respects. First, the inbuilt AI processing has dramatised the scene somewhat, by emphasising the blue of the sky and the overall contrast of the scene. It was actually a mild, slightly misty March afternoon, with that sort of diffused light that you get in early spring in Britain. Second, and to my mind more important, it has also obliterated much fine detail by smoothing out the "noise", in some areas creating smudgy, impressionistic smears that resemble a pastel drawing.  Here is my rendering of the Halide raw file:

True, to get that I had to upload the file into my computer, and run it through my usual routines. First, I had to convert it from DNG to a TIFF file in my raw processor of choice, Photo Ninja, in the process adjusting the levels of brightness, colour balance, noise, and sharpness. Then I fine tuned the TIFF file in Photoshop Elements, resulting in the version you see here. Which is a lot more work than a typical smart phone user is prepared to do, but is simply what I do routinely for every photograph I take with a "proper" camera. Why wouldn't I do that for photos taken with my iPhone?

Could I have achieved the same result by editing the JPEG file? Here are two detailed extracts from the JPEG and the final TIFF files:

Detail of rendered raw

Detail of iPhone JPEG

You might prefer the overall rendering of the iPhone JPEG – but that could easily be copied – but there's no question which is the more detailed, the more "photographic", and, crucially for me, the best option to print at anything up to its full native size of 34cm x 25.5cm at 300ppi. There's none of that JPEG impressionism about the "raw" picture, and of course the JPEG has no processing latitude: pretty much all the decisions made by the Apple processing AI are final.

The kicker for me is that as a hand-held 12 MP image that would be hard to beat by any other camera I own. Here, for example, is a detail of a very similar shot of the Hockley Viaduct taken in April last year, with the much-praised Ricoh GR. Same fixed focal length (equivalent of a 28mm wide lens) at f/5.6, 1/400 sec, ISO 100, but using a 16 MP APS-C sensor. It has its advantages but, interestingly, I had to do more work to remove optical faults like colour fringing from the Ricoh file than I did from the iPhone/Halide file. The miraculous thing is that the phone can run a top-rated pocket camera so close. And no matter how good the signal is out near Winchester, the Ricoh is completely inadequate as a phone.

[Apologies to early viewers: I posted the wrong Ricoh comparison detail]