(multi-coated)

OM-1 with mirror lockup
Vignetting = A
Distortion = slight pincushion
Aperture Center Corner
f/5      C-     C-
f/8      C      C
f/11     C+     C
f/16     B-     C+
f/22     B-     B-
f/32     B      B-
Notes: Lens shows high contrast at the expense of lower resolution, the latter which is probably due to harmonic vibrations from the OM-1 shutter and automatic diaphram mechanism.

200mm f/5 Zuiko (multi-coated) with Olympus 2X Teleconverter
OM-1n with mirror lock-up
Vignetting = B
Distortion = none!
Aperture  Center Corner
f/5 (10)  F      F
f/8 (16)  D-     D-
f/11 (22) C      C
f/16 (32) B-     B-
f/22 (44) C+     C
f/32 (64) D+     D
Notes: Lens shows good contrast at f/16 at the expense of lower resolution; remarkable lack of distortion. Poor results are the result of harmonic vibrations caused by the OM-1n shutter and automatic aperture mechanism. Nearly impossible to focus even with a Varimagnifinder and a 1-8 screen.