Archived posting to the Leica Users Group, 1998/11/27

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Subject: Re: [Leica] Laney, lens testing and 3-D effects (long: this is not Hubert)
From: Dominique PELLISSIER <pelliss@droit-eco.univ-nancy2.fr>
Date: Fri, 27 Nov 1998 22:44:59 +0100
 
Erwin wrote :

Let me be quick and mercifully: this 'edge spread width criterion' does not
exist. We have the point spread function, and the linespread function and
we have the acutance measurement. What Laney does is copying the contents
of  a research paper that is just that: a research paper. An "Ansatz" as
the Germans would say that never was followed up and went the way many
>research papers do: they evaporate.
>
>Erwin
>
##########
According to Laney, the edge spread function method has been developed
by... Leitz.(see. p.21 in the 2nd edition).One more time you gun down a
research or a method which has been made by others than you.That's neither
fair nor academic.
The method seems to have "evaporated" (why ? I'm waiting for a rational
explanation) and today Leica uses standard MTF tests.
It is interesting to quote Lothar Koelsch, the father of recent Leica
lenses, who wrote 4 papers in Leica foto (1996) on the photographic quality
of lenses : "higher are the MTF curves, better is the lens" (1996/5, p. 45).

Dominique Pellissier