I just imported a bunch of dng files from my iPhone to try in Affinity. My eye caught on a focus stack set of peppers. So I’m doing Focus Stacking with DNG files. I was curious to see if there would be any hitches. Nope. Just as easy as jpegs, except with better detail potential.
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This first image is #2 in the focus stack, focused about the level of the front edge of the orange pepper. Any time you make photos with the plane of focus not parallel to the subject plane you can expect this sort of focus fall-off.
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This second photo is the Focus Stacked one from Affinity. It is just coincidence that the examples I have shown were all stacks of 5 images. I’m just as likely to use 4 or 7, or 9, or whatever, depending on the subject.
If you try Focus Stacking I can tell you my most common early failures were caused by the closest focus position not being close enough the keep the very nearest parts of the subject in focus. It’s a good idea to make an extra shot at either extreme just to be sure.
If you decide to try Focus Stacking using a manual focus camera app rather than a focus Stacking app I think a good candidate for a Focus Stacking camera is Prime, because: it shoots RAW, it has an excellent focus peaking display so you get a much better idea of the area in focus, and it has a long focus scale up the left side of the frame as another guide to your focus position. It appears I made this focus stack set in PureShot using manual focus.
Can you guess I was from the f16 school of thought when I photographed with larger format cameras. Actually, the large view camera people were in the f64 club. With my smaller 4 x 5" view camera, the more common size, f22 was good enough. On top of that, with a view camera you have tilt and shift movements allowing you to tip the lens forward and down toward the subject, in this case, which would actually move the plane of focus to be on the same plane as the flat surface of the peppers. And the 4 x 5" negatives or transparencies were spectacular. That’s how you shoot black and white!