(multi-coated)

OM-1 with mirror lockup
Vignetting = B+
Distortion = none
Aperture Center Corner
f/6.3    C+     C+
f/8      C      C-
f/11     C+     C+
f/16     B-     B-
f/22     B-     B-
f/32     B-     C+
Notes: Moderately low contrast images; good balance on tripod; good ease of use on a tripod or handheld due to long travel helical focusing and compactness; difficult to focus in overcast sunlight (EV12).

OM-2000 with mirror and diaphram prefire
Vignetting = none
Distortion = Slight pincushion
Aperture Center Corner
f/6.3    C+     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 images.

400mm f/6.3 Zuiko (multi-coated) with Olympus 1.4X Teleconverter
Vignetting = not determined
Distortion = slight pincushion
Aperture  Center Corner
f/6.3 (9) not determined
f/8 (11)  not determined
f/11 (16) not determined
f/16      C+     C-
f/22      C+     C
f/32      C      B-