iPhone 11 UWA Camera : Disturbing Discoveries

October 18, 2019 by

After just spending a day’s worth with the iPhone 11 Pro ultra wide angle camera, I’ve discovered a few things everyone should be aware of. I’m rather tired of Apple’s half-assed approach to everything photography related. This is not a whining of a 20-something reviewer. This is from someone who wasted months of his life to transform Apple’s incomplete, amateurish APIs to something suitable for professional photo apps, and wrote exposure calculation, image encoding/decoding/display and color space transformation code along the way.

To anyone reading this at Apple: I’m open to provide you with consultancy to help get your act together and make a truly pro-level camera device / API.

No RAW

Take a look on any JPG file from the ultra wide camera. You’ll see heavy smearing and exaggerated chromatic aberration as you approach the corners. These are telltale signs of distortion correction going on (I have quite a lot of experience in this since I wrote the world’s first wide angle converter real-time distortion correction code on iOS for the Mark II Artist’s Viewfinder six years ago).

Which means that the laws of physics still apply, and supports my suspicion that the ultra wide angle camera in fact has a pretty awful tiny lens, with huge amount of distortion. And Apple doesn’t want to advertise this, so rather turned RAW capture completely off for this camera. Why? Leica, Nikon, Panasonic all do software distortion correction for expensive lenses, and the photographer at least have the freedom to correct it or leave the distortion in place for artistic purposes. (That I would never buy a 5 grand lens that require distortion correction is a tale for another day.)

The professional approach would be to provide RAW capture, and include distortion correction data inside the DNG so that RAW converters could pick it up (with the WarpRectilinear opcode).

2-3 Stop Vignetting

iPhone 11 Pro Max ultra wide camera vignetting

Now seriously. When one does distortion correction, why vignetting correction isn’t in place is beyond me. The above shot is just a wall shot under daylight, and not something suitable for exact measurements. I might do it later on, but currently this is enough to illustrate how much vignetting the image suffers from.

Again, the professional approach would be to correct this in JPG images and live video stream (or even better, provide an API to be able to control the correction), and include the necessary correction data inside the DNG files (FixVignetteRadial opcode).

No Focusing

This camera has a fixed focus lens. Read: no focusing of any kind. With such an ultra wide lens, the lack of focusing ability is mostly disguised by huge depth of field. But don’t expect to use it for ultra wide closeups.

Conclusion

Anyone touting this camera as a professional grade, DSLR (or even medium format) contender must live in a reality distortion field, powered by a huge marketing budget. Over-processed Apple JPGs suck. They always sucked. Not having proper RAW capture on the ultra wide camera is a huge drawback of the iPhone 11 series, hindering their usability for professional image capture.

  ☕ ☕ ☕

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Filed Under: Photo Equipment, Photo Technique Tagged With: , , , ,

Why iPhone RAW is a Big Deal

October 23, 2016 by

iOS 10 brought the capability to get the RAW image data from the camera and save it as a DNG file. It elevates the quality of iPhone images to a whole new level (for those who care). The following image tells it all.

Click the image for actual pixels display on non-Retina screens

Click the image for actual pixels display on non-Retina screens

On the left is how the iPhone renders the image, on the right my version converted from DNG and tweaked to taste in Capture One. Both show the actual pixels (100% magnification). Red areas are the overexposed parts. The images were captured as RAW+JPG in the upcoming Mark II Artist’s Viewfinder 5.0, so they represent the exact same moment.

With shooting RAWs you can avoid most of the pitfalls of iPhone image processing (I know them from experience):

  • Over-sharpening, which ruins images with already high contrast edges, such as tree branches against the clear sky.
  • Excessive noise reduction – usually on an unnecessary level, even at ISO 25. You know, the blotchy look at 100% which looks downright ugly.
  • Unrealistic color. Apple processes the images for punch, which is good for making your friends envious on social networking sites, but is a problem when you want to actually use them (the images, not your friends) as real photographs.
  • Sometimes overdone light falloff correction. You know, when the sky is brighter in the corners than in the center.

You also get more headroom for recovering overexposed areas (they are also better by default because of the lower contrast), but on the other hand you need to correct corner light falloff by hand.

To my eye the difference is so large that I won’t use JPGs any more when I’m photographing with the iPhone (which happens a lot, since it’s always in my pocket). No, they are not challenging DSLR (or even large sensor point and shoot) quality, but are way more usable than the JPGs.

Filed Under: Photo Software, Photo Technique Tagged With: , , , ,