Character of lenses

[T3D John Fairstein <jfairstein@xxxxxxx>]

John Bercovitz writes: "They [Zeiss] mentioned that under the best of
conditions, a contrast of 5% was sufficient for resolution by the human
eye."

See http://www.kodak.com/ppiHome/technicalPubs/ePubs/e55/f002_0489ac.gif
for the MTF curves for Kodachrome 64. Extending the curve down to 5%
yeilds a little over 100 lines/mm -- about what a German Realist f2.8
lens will resolve.

Surprisingly, the K25 curve (see
http://www.kodak.com/ppiHome/technicalPubs/ePubs/e55/f002_0485ac.gif) is
slightly less than 100 lines/mm at 5% modulation.

I have been unable to find similar curves for Fuji Velvia or Kodak Elite
II 50 for comparison.

Subjectively, the Realist lenses seem to have more contrast than other
50s era lenses.

Regarding the "character" of lenses, most of my favorite 3D slides were
taken with a 3.5 Realist. Allow me to speculate that the slight
vignetting and fall-off of sharpness at the edges tends to draw the eye
to the center of the image.

Rambling on, one of my favorite 2D lenses, the 60mm Zeiss Distagon for
the Hasselblad, imparts a wonderful roundness to the subject.


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