From: Carl Weese (cweese@earthlink.net)
Date: 03/28/01-08:04:14 AM Z
Sandy,
Afraid I don't know lens design. Pierce (his double major at Princeton in
the late fifties was physics/English) could speak with the Leitz designer in
his own language. What I do understand is that all lenses are compromises
and that the balance can favor simple things like resolution vs contrast
(Commercial Ektars were designed for maximum contrast with little regard for
resolution, according to Arthur Kramer, because Kodak reasoned that the
lenses were going to be used mainly on 8x10 cameras to shoot commercial
pictures for full page magazine ads: resolution was irrelevant at 125%
magnification, but maximum internal contrast assisted the whole color
reproduction process of the 40's and 50's. It also makes these lenses
splendid for b&w contact printing) while bokeh characteristics are just a
more complex aspect of these compromises. Oren Grad, who can read them in
the original Japanese, says that Japanese photo mags are extrememly fanatic
and one of their fascinations is bokeh (properly rendered bokeru) with
carefully arranged test subjects used in every lens test to see how it
handles light, dark, shiny, matt, etc subjects in the out of focus zone.
BTW, the number of blades in the lens iris is apparantly very important,
with more blades and a smoother circle making for smoother focus. Despite
this interest among the fanatic amateurs, Japanese manufacturers tend to lay
their burnt offerings at the altar of resolution (I'm paraphrasing Pierce)
while the Germans tend to look more at the overall performance of the lens.
The Leitz summicrons and the Rodenstock large format Apo Sironar S series
are considered by many afficianodos to have the finest bokeh of all
lenses---and they are hands-down my favorite lenses. Wish I could use them
for banquet cameras.
---Carl
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