Canon FD 50-135mm f/3.5 bayonet mount
Canon EF with mirror and diaphragm prefire

@ 50mm setting
Vignetting = B+ @ f/3.5, A- @ f/5.6, A thereafter
Distortion = pronounced barrel

Aperture Center Corner
f/3.5    B-     B-
f/5.6    B+     B+
f/8      A-     A-
f/11     B+     B+
f/16     B      B+
f/22     B      B
f/32     B-     B-

Notes:
very high contrast at f/11 through f/32;
high contrast at f/5.6 to f/8;
moderate contrast at f/3.5.

@ 90mm setting
Vignetting = B+ @ f/3.5, A- @ f/5.6, A thereafter
Distortion = pronounced pincushion

Aperture Center Corner
f/3.5    B+     B
f/5.6    A-     A-
f/8      A-     A-
f/11     A      B+
f/16     A-     B+
f/22     B      B
f/32     B-     B-

Notes:
moderately high contrast at f/3.5;
high contrast at f/5.6, and f/16 through f/32;
very high contrast at f/8 anf f/11.

@ 135mm setting
Vignetting = B @ f/3.5, A- @ f/5.6 & f/8, A thereafter
Distortion = extreme pincushion

Aperture Center Corner
f/3.5    C-     C-
f/5.6    B-     B
f/8      B-     B-
f/11     A-     B+
f/16     B+     B
f/22     B      B
f/32     B      B

Notes:
low contrast at f/3;
moderate contrast at f/5.6, f/8 and f/32;
moderately high contrast at f/11 through f/22.