Here are some new data that should be interesting to Zuikoholics:
80mm f/4.0 Auto 1:1 Macro Zuiko (multi-coated)
OM-4 with mirror and diaphragm prefire, used on a 25mm auto extension
tube
Vignetting = B @ f/4, A- @ f/5.6, A thereafter
Distortion = slight pincushion
Aperture Center Corner
f/4 C+ C
f/5.6 B+ B-
f/8 A- B
f/11 A- B
f/16 A- B
f/22 B B-
f/32 B- B-
Note: Moderate contrast, except low at f/32. Since this lens is
optimized for 2:1 to 1:2 reproduction ratios, these test results at 1:40
are for experimental purposes only. Optimum apertures f/8 through f/16.
16mm f/3.5 Zuiko Fisheye (multi-coated)
OM-4Ti w/ mirror and diaphragm prefire
Vignetting: B @ f/3.5 to f/16, A- at f/22
Distortion: NA
Aperture Center Corner
f/3.5 A+ C+
f/5.6 A+ B-
f/8 A+ B
f/11 A+ B+
f/16 A A-
f/22 A A-
Note: High contrast at f/3.5 & f/22, very high contrast elsewise. The
center subject size is greatly magnified in relation to non-fisheye
lenses. Likewise, corner subject matter is greatly reduced in
magnification. Thus, the resulting SQF grades are not directly
comparable to those for non-fisheye lenses. But, my general impression
of the center image quality was that it is of the highest order of
magnitude from f/3.5 to f/11, although f/16 is perhaps the optimum
aperture overall.
I also replaced the 35-70mm f/3.6 test results with a fresh test based
on an OM-4 using mirror and diaphragm prefire. Significant improvements
resulted versus just mirror lockup in the OM-1. I suspect this lens will
become a bit more popular as folks discover all the new A's in the data.
At f/11, this lens is stellar across its focal length range. It is
pretty impressive for such an old design.
Gary Reese
Las Vegas, NV
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