Yes, you might be right. The softness might be due to the subjects. I do a lot of environmental portraits at relatively close ranges and here the corners are less noticeable anyway. My impression is that the lens really shines at these ranges. I have some very sharp portraits in the 1m-0.35m range. Renders beautifully too. At low apertures I’ve noticed some corner softness, but not enough to bother me. Stopped down the lens seems sharp corner to corner. I scan with a Pakon that is not that affected by film curling so that might be another factor..
Another thing that seems to go wonky on these cameras is the auto focus. I have one copy that seems to want to focus on infinity about 80% of the time, and it seems others have similar problems..
