Noflexar 400mm f/5.6 (Novoflex System) OM-1 with mirror lockup & second tripod supporting hood - camera upside down with tripod head horizontal Vignetting = A- Distortion = none Aperture Center Corner f/5.6 B- C+ f/8 B B- f/11 A- B- f/16 A B f/22 B+ B f/32 B- B- Notes: Exceptional ease of focusing handheld due to Novoflex rapid focusing system; high contrast at f/8 to f/16; remarkably bright viewfinder image for a super telephoto of this aperture, although some difficulty in finding correct focus when used in typical overcast sunlight (EV12). OM-2000 with mirror prefire and second tripod supporting hood - camera rightside up, but mounted to tripod with head oriented vertically; different lens than above tests. Vignetting = A- @ f/5.6, A thereafter Distortion = slight pincushion Aperture Center Corner f/5.6 A- B- f/8 A B f/11 A B+ f/16 A B+ f/22 A- B f/32 B+ B+ Notes: High contrast; slightly cooler images than with a 400mm f/6.3 Zuiko. Best employed on a tripod with a tripod collar forward of the pistol grip - but unavailable that way for testing. OM-4T with mirror & diaphragm prefire and Bogen Telephoto Lens Support - same lens as OM-2000 test. Vignetting = A- @ f/5.6, A thereafter Distortion = slight pincushion (none?) Aperture Center Corner f/5.6 A- C f/8 A C+ f/11 A B- f/16 A B+ f/22 A- A- f/32 B+ B Notes: A workable combination using the Bogen Telephoto Lens Support, offering much better lens support than previous tripod mounted schemes. Causes a blurry focusing images away from center on a 2-4 focusing screen - a combination that should be considered unusable. High contrast in center and moderate contrast images in corner at f/5.6 and f/8; very high contrast in center and moderately high contrast in corner at f/11; very high contrast in center and high contrast in corners at f/16; moderately high contrast in center and corners at f/22 to f/32. f/16 is optimum aperture. Noflexar 400mm f/5.6 (Novoflex System) with Olympus 1.4x Teleconverter OM-1 with mirror lockup and second tripod supporting hood Vignetting = B @f/5.6 (8), B+ @f/8 (11), A- @f/11 (16), A thereafter Distortion = slight pincushion Aperture* Center Corner f/5.6 (8) C- D+ f/8 (11) C B- f/11 (16) B- C+ f/16 (22) B B- f/22 (32) B B- f/32 (44) C C Notes: *Effective aperture in parenthesis (). Moderately high contrast but lack of resolution. OM-4T with mirror & diaphragm prefire with Bogen Telephoto Lens Support & monopod supporting camera - different lens than above. Vignetting = B @f/5.6 (8), B+ @ f/8 (11), A- @f/11 (16), A thereafter Distortion = moderate pincushion Aperture* Center Corner f/5.6 (8) C C f/8 (11) C+ C f/11 (16) B- B- f/16 (22) B B- f/22 (32) B+ B f/32 (44) B- B- Notes: *Effective aperture in parenthesis (). Moderately high contrast in center at all apertures; moderate contrast images in corners at all apertures except f/22 (32), where they are moderately high. Noflexar 400mm f/5.6 (Novoflex System) with Olympus 2X-A Teleconverter OM-4T with mirror & diaphragm prefire with Bogen Telephoto Lens Support & monopod supporting camera. Vignetting = C @f/5.6 (11), B @ f/8 (16), A thereafter Distortion = pronounced pincushion Aperture* Center Corner f/5.6 (11) D+ C- f/8 (16) C C f/11 (22) B- B- f/16 (32) B B- f/22 (44) B- B- f/32 (64) C+ C Notes: *Effective aperture in parenthesis (). Moderately low contrast in center and corners atf/5.6 (11); moderate contrast in center and corners at f/8 (16); moderately high contrast in center and moderate in corners at f/11 (22) to f/22 (44); moderate contrast in center and moderately low in corners at f/32 (64).