12-02-2011, 10:49 AM
[quote name='Klaus' timestamp='1322822786' post='13432']
Field curvature has nothing to do with auto-correction nor can it be corrected anyway - this is related to a curved focus field rather than a more or less flat one. The tested sample had a focus field where the border/corner focus was extremely pulled towards you so infinity focus (actually mid field focus) was lost.
I had to stop down to f/11 to achieve a decent corner sharpness. At f/5.6 even the mid field was already bad.
[/quote]
Thanks, i think you will find your sample was fine. I experience this also.
Field curvature has nothing to do with auto-correction nor can it be corrected anyway - this is related to a curved focus field rather than a more or less flat one. The tested sample had a focus field where the border/corner focus was extremely pulled towards you so infinity focus (actually mid field focus) was lost.
I had to stop down to f/11 to achieve a decent corner sharpness. At f/5.6 even the mid field was already bad.
[/quote]
Thanks, i think you will find your sample was fine. I experience this also.