(multi-coated) 
OM-2S with mirror and diaphragm prefire, dual tripods - one on the camera and one on the tripod mount of the lens 
Vignetting: None Distortion:  slight pincushion 
Aperture  Center    Corner 
f/11      C-        C 
f/16      C         C+ 
f/22      B         B+ 
f/32      B         B 
f/45      B         C+ 

Notes: Very low contrast at f/45, moderately low contrast at f/11, moderate contrast at f/16 to f/32. Essentially impossible to use with a 2 series focusing screen, apparently due to the optical properties of those screens.  Difficult to focus due to poor performance wide open (i.e., the aperture focusing is done at).