(single-coated)

OM-1 with mirror lock up
Vignetting = A-?
Distortion = none to very slight pincushion
Aperture Center Corner
f/4      D+     D
f/5.6    D+     C-
f/8      C      C
f/11     B-     C
f/16     B      B-
f/22     B      C+
f/32     B      C+
Notes: Slightly longer shutter speeds at a given aperture versus the 200mm f/4 multicoated test. Low contrast images.

200mm f/4 Zuiko (single-coated) with Olympus 2X Teleconverter
OM-1 with mirror lockup
Vignetting = B+?
Distortion = pincushion
Aperture   Center Corner
f/4 (8)    D+     D-
f/5.6 (11) C      C-
f/8 (16)   C+     C-
f/11 (22)  B-     C
f/16 (32)  B-     C+
f/22 (45)  C+     C
f/32 (64)  C      C-
Notes: Slightly longer shutter speeds used at a given aperture versus the 200mm f/4 multicoated test; thus the effects of camera shake lessened. Low contrast images. No performance degradation at f/11 over the 200mm f/4 without teleconverter.