(multi-coated) Vignetting = A Distortion = none All tests shot with the same lens, in 9+ condition. These multiple tests were done to determine the effects of vibration from shutter travel and the auto diaphram mechanism. OM-2000 with mirror & auto diaphram prefire, lens supported by Bogen Telephoto Lens Support Aperture Center Corner f/4 B B- f/5.6 B+ B f/8 A- B f/11 A- B+ f/16 B+ B+ f/22 B+ B+ f/32 B B- Notes: Statistically insignificant differences to the OM-4 test below, perhaps indicating little advantage to a vertical traveling shutter in the OM-2000. OM-4 with mirror & auto diaphram prefire, lens supported by Bogen Telephoto Lens Support Aperture Center Corner f/4 B B- f/5.6 A- B+ f/8 A- B+ f/11 A A- f/16 A A- f/22 B+ B+ f/32 B B- Notes: Apparently superior results versus using an OM-1 (see below). Zuiko lenses in this weight and length class need additional support, as well as mirror and aperture prefiring, to obtain best results. OM-1 with mirror lock up, shutter overhaul and Bogen Telephoto Lens Support Aperture Center Corner f/4 C B f/5.6 B- B f/8 B B f/11 B+ B+ f/16 B B+ f/22 B+ B+ f/32 B+ B+ Notes: Test immediately following is with the same camera. Differences are significant at the 1/3rd grade level (slides evaluated as pairs). Differences are significant at full letter grades levels only in comparisons to the OM-4 and OM-1 with untuned shutter. OM-1 with mirror lock up and shutter overhaul Aperture Center Corner f/4 D C+ f/5.6 C- C f/8 C C+ f/11 B- B- f/16 B- B- f/22 B+ B+ f/32 B B Notes: Vertical shake evident atf/5.6 (=1/60th sec. exposure) and f/8 (=1/30th sec. exposure). Test immediately preceeding is with the same camera. Differences are significant at the 1/3rd grade level (slides evaluated as pairs). Differences are significant at full letter grades levels only in comparisons to the OM-4 and OM-1 with untuned shutter. OM-1 with mirror lock up and untuned shutter Aperture Center Corner f/4 C C f/5.6 D+ C- f/8 C- C f/11 C B- f/16 C+ B- f/22 B- B- f/32 B- B- Notes: Low mass of OM camera body probably results in camera shake for shutter speeds of 1/60 to 1/2 sec., in spite of tripod, cable release and mirror lockup precautions. Better wide open performance attributable to lack of additional vibration from the automatic diaphram. 200mm f/4 Zuiko (multi-coated) with Olympus 2X Teleconverter OM-4T with mirror and diaphragm prefire Vignetting = B @f/4 (8), A- @f/5.6 (11), A thereafter Distortion = slight pincushion Aperture* Center Corner f/4 (8) B C f/5.6 (11) B+ B f/8 (16) B B f/11 (22) A- B f/16 (32) B B- f/22 (45) B- B- f/32 (64) C C Notes: *Effective aperture in parenthesis (). Used a Bogen Telephoto Lens Support for additional stability. A suprisingly useable combination, both performance- and handling-wise. Moderate contrast in center and moderately low contrast atf/4 (8); moderate contrast in center and corner atf/5.6 (11) and f/16 (32); moderately high contrast in center and moderate in corner atf/8 (16) and f/11 (22); moderately low contrast in center and corner at f/22 (44) and f/32 (64).