Archived posting to the Leica Users Group, 1998/04/23
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Eric Welch,
>>Lens design is based not only,,,but, experience, & a tradition, such as
Leicas<<
>>to set certain performance goals<<
Per an interview, with Lothar Kolsch, "Color Foto", dated 12/95 were the
following quotes; 1.) He was asked, "Which test method is best", He
answered, " The most
neutral & currently best method, in my view, are MTF measurements over
several local frequencies, 5-40, or even 60 LPM". 2.) "The art of lens
development is not only to come up with a contrast at 5 LPM that is 100% &
a resolution at 40 LPM that is as high as possible; but, wide open as well
as stopped down".
There was much, much more; but, I thought the article surely signaled a
change in Leica tradition as evidenced by lenses such as the 180 f2.8 apo (
& many others )
relative to Leica lenses of the past that emphasized contrast over
sharpness. It's clear that Lothar Kolsch is attempting ( & succeeding ) to
optimally blend contrast & sharpness thru all the f-stops & measuring his
success via MTF diagrams.
Don't get me wrong, I like the older tradition as well; i.e, I'm going to
keep my R-80
Summilux. However, I really like the current batch of high performance
lenses in which contrast & sharpness are optimized.....& only Leica can
build :-)!
Tom D.