Nikon Nikkor AF 50mm f/1.8
Nikomat FTN with mirror and diaphragm prefire

Vignetting = B- @ f/1.8, A thereafter
Distortion = slight barrel

Aperture Center Corner
f/1.8    B      B-
f/2.8    B+     B
f/4      B+     B+
f/5.6    B      B+
f/8      A-     A-
f/11     B+     B+
f/16     B      B