Tokina 100-300mm f/4 AT-X
OM-4T with mirror and diaphragm prefire

@ 100mm
Distortion: slight waveforming with no tendencies
Vignetting: B+ @ f/4, A elsewise
Aperture Center Corner
f/4      B      B+
f/5.6    B      A-
f/8      B      B+
f/11     B+     B+
f/16     B+     A-
f/22     B      B+
f/32     B     B+
Notes: Moderately high contrast throughout.

@ 200mm
Distortion: none
Vignetting: B+ @ f/4, A elsewise
Aperture Center Corner
f/4      B      C+
f/5.6    A-     B
f/8      A      B
f/11     A-     A-
f/16     B+     B+
f/22     B+     B+
f/32     B-     B
Notes: Moderately high contrast throughout.

@ 300mm
Distortion: slight waveforming with slight pincushioning tendency
Vignetting: B @ f/4, A- @ f/5.6, A @ f/8
Aperture Center Corner
f/4      C      C
f/5.6    B-     C+
f/8      B      B-
f/11     B      B
f/16     B-     B-
f/22     B-     B-
f/32     B-     B-
Notes: Moderately high contrast throughout.