01-24-2011, 09:58 PM
"Center and border sharpness is excellent at any aperture, from wide open down to f/11 (where diffraction begins to reduce resolution)."
I'm a bit puzzled, I have to say. I see this figure - f/11 - in every review of a sharp lens, and also, I see that the resolution starts dropping after f/4 or f/5.6 according to the MTF charts, in every review of a sharp lens. So, my interpretation is that excellent lenses are diffraction limited already by f/5.6 or f/8, not f/11, on 10 MP APS-C. Am I missing something?
I'm a bit puzzled, I have to say. I see this figure - f/11 - in every review of a sharp lens, and also, I see that the resolution starts dropping after f/4 or f/5.6 according to the MTF charts, in every review of a sharp lens. So, my interpretation is that excellent lenses are diffraction limited already by f/5.6 or f/8, not f/11, on 10 MP APS-C. Am I missing something?