210mm lens which is sharpest aperture

**robc** · 4-Dec-2006, 08:19

if you have a 210mm lens, which aperture do you consider to be its absolute sharpest ignoring dof.

**Walter Calahan** · 4-Dec-2006, 08:56

As I said on the other posts:

What does it matter? Sharpness is only a tool for translating one's vision to paper.

**Christopher Perez** · 4-Dec-2006, 09:46

For most applications, this is pretty meaningless. We stop the lens down for DOF and don't notice that in absolute terms, resolution is diffraction limited by f/22, or f/16 (in the better modern plasmats). In some cases of four element airspace copy lenses, or tessar formula optics, you can get the best resolution wide open. But then, commercially available film has a difficult time capturing all that information in the typical scene contrast ratio of 6 to 1.