Hi, question for all 100-400 owners, please indicate at what aperture you found your lense to have the sharpest IQ ...
Read in various threads that it is around 7.1 or 8.0 ...
2nd question, I generally shoot Avian with the following settings:
Shutter Priority = 1/1250
Iso = 800 or lower (however light dependant)
AF = Centre spot/point
The resulting aperture is around 5.1/5.6, question is if I decrease the SS to say 1/500 it should increase the aperture right (keeping light conditions similar) ?