Leitz 90mm f/2 Summicron-R (1978 era 3-cam)
Leicaflex with mirror and diaphragm prefire
Vignetting = B @ f/2, A- @ f/2.8, A thereafter
Distortion = slight pincushion
Aperture Center Corner
f/2*     C+     C
f/2      B      B
f/2.8    B+     B
f/4      B+     A-
f/5.6    A      A
f/8      A-     A-
f/11     A      A
f/16     A      B
Notes: * = Tested with a B+W 010 filter. Moderately high contrast images at f/2; high contrast images at f/2.8 and f/16; very high contrast at f/4 and f/11; extremely high contrast images at f/5.6 and f/8. Lens condition 9+ (KEH=Ex+). Paired SQF grade and contrast comparison to the 90mm f/2 Zuiko Macro test done on a OM-2000, with SQF differences significant at the 1/3 grade level.