Originally posted by biz-engineer Note from exif: you closed the aperture to f16, if the camera was a eye level, you could have opened up to f6.0 for 30mm, or f8 to be on the safe side, give more overall detail.
Thanks for the suggestion. I'll definitely less narrow apertures with the lens. According MTF line, the sharpest aperture at 15mm is f5 and the sharpest aperture at 30mm is f6.3. Now I never follow MTF line because I'm trying to get everything in focus and that requires stopping down. With a lens like the DFA 28-105, I'll shoot almost exclusively at f11. With the wider DFA 15-30, I may be able to get away with f8 or even faster. I'll have to experiment and see what works for what I'm trying to do. And while it is true that you lose detail as you stop the lens down from its MTF sweet spot, I've found that in practice you don't actually lose that much provided you don't go much past f16.