Canon FD 35mm f/2.8 bayonet mount
Canon EF with mirror and diaphragm prefire

Vignetting = B- @ f/2.8, A- @ f/4 & f/5.6, A thereafter
Distortion = barrel

Aperture Center Corner
f/2.8    B+     B
f/4      A-     B+
f/5.6    A      A
f/8      A-     A-
f/11     B+     B+
f/16     B      B
f/22     B-     B-

Note:
high contrast at f/4 and f/11 through f/22;
very high contrast at f/5.6 to f/8;
moderately high contrast at f/2.8.