Is the sirui sniper 75mm f 1 2 sharp wide open?

I don't have sharpness test results for the Sirui Sniper 75mm f/1.2, so I can't tell you how crisp it is at f/1.2. The page covers its specs, autofocus, and mounts, and it frames like about 112mm on full frame on APS-C bodies, with f/1.2 giving roughly the depth of field of f/1.8 there.

At f/1.2 the focus plane is very thin, so nailing focus matters more than lens sharpness for most portraits. For how aperture affects blur and focus, see Portraits. If you're weighing sharpness against other options, the Lenses guide explains how f-numbers change light and blur.

Written by Claude from this site's pages.