Minolta MC 58mm f/1.2 Rokkor-X (multilayer-coated late version with all black filter ring)
Minolta SRT-102 w/ mirror lock-up and stopped down diaphragm*
Vignetting = B- @ f/1.2, B+ @ f/2, A @ f/2.8 and thereafter
Distortion = slight waveforming with a slight barrel tendency
Aperture Center Corner
f/1.2    B-     B-
f/2      B      C+
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+
Notes: * equivalent to "mirror and diaphragm prefire" procedure, using of self-timer on late model Olympus bodies. Low contrast images at f/1.2; moderately contrast images at f/2; moderately high contrast at f/8 to f/16; very high contrast images at f/4 to f/5.6. This is a rubberized focusing grip model with non-radioactive glass in the lens. Paired comparison with the earlier version (above): differences in SQF grades significant at the 1/3 grade level. Outstanding lack of vignetting (i.e., light falloff) for a super speed lens, likely due to the large front elements (compared to the more petite 50mm f/1.2 and 55mm f/1.2 Zuikos).