Archived posting to the Leica Users Group, 1997/08/09

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Subject: Re: 35mm vs 2 1/4 (again)
From: Erwin Puts <imxputs@knoware.nl>
Date: Sat, 09 Aug 1997 13:36:40 +0200

LUGgers,
A year ago I posted the first mail to discuss the relative performance
of 35 (Leica) and 120 (H'blad). The pro's and cons were evenly divided.
I stated that up to 14 times enlargement there was no visible difference
between a Leica print and a H'blad print enlarged to equivalent print
size (therefore lower enlargement factor).
I also stated that in the case of Leica the utmost care had to be taken
to technical issues as Leica is at these enlargements working at the
cutting edge of its optical potential. Expose/develop more than a 1/3
stop from optimum and image quality is gone! 120 users can take a much
more relaxed stand. 
The resolution is not the issue here. As a matter of fact. Leica lenses
have a higer resolution, but is contrast modulation that counts. At
40lp/mm (Leica and Zeiss can handle that easily) the Leica has a much
higher MTF value and therefore can handle the definition of very fine
detail as good or better than  Zeiss at lower enlargement factors.
When both are blown up to the same enlargement factor Leica simply loses
out. BUt not because of resolution or contrast , but from the emulsion
side of the equation.
As the American car makers used to say in the golden days of V8 engines.
"There is no substitute for cubic inches" and so there is no substitute
for image area on the neg or tranny.
It is here that the information theory comes in: if on a given area you
can pack a certain amount of pixels, than if you can bring that same
amount of pixels on a bigger area, the information recording capacity is
just better. There is more grain available to record the same quantity
of pixels and so the information is recorded with less loss, when
enlarging.
As usual: if a person is unhappy with an instruments recording
capability; it is mostly the user who has to upgrade his expertise, not
change the instrument.
Erwin