Blade Canyon
Senior Member
I watched some great Joel Grimes videos about shooting on location with artificial light, but he also made a big deal about sharpness. He uses a tripod for everything, and he had a good discussion about finding each lens's sweet spot aperture for sharpness. Aberration is a problem at open apertures, and diffraction is a problem at small apertures. So I decided to test my lenses. Here's the first one, a tiny detail in a photo shot at various apertures with the 50mm 1.8D:
My D800 was set on a tripod and I manually focused using zoomed live view. After that I did not touch the focus or move the camera at all except to change the F stop. I tried to keep the shutter speed the same by using a speedlight, but you can see the lighting was not even across the board.
Still, the results are consistent. The best f stop sharpness for my lens is obviously in the 7 to 9 range. That's higher than I thought it would be because most articles say three stops over the widest is usually best, which would have been 5.6. Maybe that is the best, because now I see I skipped pretty far from 5 to 7. F 11 looks pretty good, too. I'll shoot this lens with confidence in that range.
My D800 was set on a tripod and I manually focused using zoomed live view. After that I did not touch the focus or move the camera at all except to change the F stop. I tried to keep the shutter speed the same by using a speedlight, but you can see the lighting was not even across the board.
Still, the results are consistent. The best f stop sharpness for my lens is obviously in the 7 to 9 range. That's higher than I thought it would be because most articles say three stops over the widest is usually best, which would have been 5.6. Maybe that is the best, because now I see I skipped pretty far from 5 to 7. F 11 looks pretty good, too. I'll shoot this lens with confidence in that range.
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