thompsonkirk
Member
This weekend I've been experimenting with focus stacking on GFX landscape files. I'm a bit surprised at the results and would appreciate hearing about different experiences.
It's about 3 months since I switched from A7r2 to GFX, and I've been concerned about DOF and about diffraction with lenses stopped down to compensate for longer lenses/larger sensor. I almost bought a used Hartblei tilt-shift lens to avoid stopping down, but I realized that my landscape shots too often have overhanging trees, so tilting the lens to increase DOF wouldn't be successful. Hence my interest in focus stacking.
I'm not posting samples for pixel-peeping, because the things I've noticed so far were pretty easy to see:
1. Using the 32-64 lens, diffraction isn't as much a problem as I thought it would be, given my customary print size (17x22 paper). F16 is acceptable, but I did my single-file comparison shots at f22 to create a worse-case scenario.
2. Focus stacking 3 to 5 files shot at f8 with Photoshop produced quite good results from the standpoint of overall sharpness. The drawback of PS's focus stacking was that it sometimes missed very small areas. That is, sometimes I could see at 100% that in a midrange-focused area, there was a little gap where it should have picked up some leaves from a farther-focused file but didn't do so. The faults seemed, however, to be so minor that I didn't think they'd need manual retouching.
3. Helicon Focus disappointed me, and here especially is where I'd like to know about others' experience. While it seemed to make the stacking selections more precisely, the resulting image was never as sharp as a Photoshop-stacked comparison image. It altered tones and contrast. I tried both Method A and Method B, and tried turning down the Smoothing setting to see if that made an improvement, but it didn't. In some instances my f22 unstacked comparison image looked sharper than the Helicon versions, except with lots of foreground. The f22 and PS versions were better than Helicon in preserving color balance.
4. One advantage when using a larger aperture and focus stacking is simply the shorter exposure! At f22, leaves and branches were more likely to blow during the necessarily longer exposure. With shorter exposures at f8, I could paint in things that had moved from another layer.
5. I've ended up believing focus stacking for my kind of work (landscape, not macro, photography) is less often useful or necessary that I'd thought it would be. The 32-64 lens is excellent at f11, and loses contrast, more than it goes soft from diffraction, at smaller apertures. When using the 64mm end, or when there's a long foreground with important subject matter, I'll make several files for stacking. But I expect to need them less often than I'd anticipated.
6. I don't plan to experiment with other stacking software, because in the few instances I'll be needing it, either the less-perfect PS stacks or the apparently lower resolution Helicons give me sufficient options.
I don't think I've made any big mistakes in my experiments, and perhaps the main variable in other folks' experience is that they make larger prints than I do, and are thus more concerned about diffraction.
Question: I'm a beginner at this; so has your mileage varied significantly from mine?
Kirk
PS, I posted one of the images here – 3 files with Photoshop stacking: https://www.getdpi.com/forum/medium...-backs/4730-fun-mf-images-447.html#post749527
It's about 3 months since I switched from A7r2 to GFX, and I've been concerned about DOF and about diffraction with lenses stopped down to compensate for longer lenses/larger sensor. I almost bought a used Hartblei tilt-shift lens to avoid stopping down, but I realized that my landscape shots too often have overhanging trees, so tilting the lens to increase DOF wouldn't be successful. Hence my interest in focus stacking.
I'm not posting samples for pixel-peeping, because the things I've noticed so far were pretty easy to see:
1. Using the 32-64 lens, diffraction isn't as much a problem as I thought it would be, given my customary print size (17x22 paper). F16 is acceptable, but I did my single-file comparison shots at f22 to create a worse-case scenario.
2. Focus stacking 3 to 5 files shot at f8 with Photoshop produced quite good results from the standpoint of overall sharpness. The drawback of PS's focus stacking was that it sometimes missed very small areas. That is, sometimes I could see at 100% that in a midrange-focused area, there was a little gap where it should have picked up some leaves from a farther-focused file but didn't do so. The faults seemed, however, to be so minor that I didn't think they'd need manual retouching.
3. Helicon Focus disappointed me, and here especially is where I'd like to know about others' experience. While it seemed to make the stacking selections more precisely, the resulting image was never as sharp as a Photoshop-stacked comparison image. It altered tones and contrast. I tried both Method A and Method B, and tried turning down the Smoothing setting to see if that made an improvement, but it didn't. In some instances my f22 unstacked comparison image looked sharper than the Helicon versions, except with lots of foreground. The f22 and PS versions were better than Helicon in preserving color balance.
4. One advantage when using a larger aperture and focus stacking is simply the shorter exposure! At f22, leaves and branches were more likely to blow during the necessarily longer exposure. With shorter exposures at f8, I could paint in things that had moved from another layer.
5. I've ended up believing focus stacking for my kind of work (landscape, not macro, photography) is less often useful or necessary that I'd thought it would be. The 32-64 lens is excellent at f11, and loses contrast, more than it goes soft from diffraction, at smaller apertures. When using the 64mm end, or when there's a long foreground with important subject matter, I'll make several files for stacking. But I expect to need them less often than I'd anticipated.
6. I don't plan to experiment with other stacking software, because in the few instances I'll be needing it, either the less-perfect PS stacks or the apparently lower resolution Helicons give me sufficient options.
I don't think I've made any big mistakes in my experiments, and perhaps the main variable in other folks' experience is that they make larger prints than I do, and are thus more concerned about diffraction.
Question: I'm a beginner at this; so has your mileage varied significantly from mine?
Kirk
PS, I posted one of the images here – 3 files with Photoshop stacking: https://www.getdpi.com/forum/medium...-backs/4730-fun-mf-images-447.html#post749527
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