(single-coated) OM-2000 with mirror and aperture prefire and Bogen Telephoto Lens Support Vignetting = A Distortion = slight pincushion Aperture Center Corner f/5 B- B- f/8 B B- f/11 B+ B f/16 A- B+ f/22 B+ B f/32 B B- Notes: Moderately low contrast.