Archived posting to the Leica Users Group, 2000/11/09

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Subject: [Leica] sensitometry and gradation
From: Robert Appleby <robert.appleby@tin.it>
Date: Fri, 10 Nov 2000 08:37:12 +0100

>>>>>
lots and lots of stuff, then:

Second, you obviously know very little about tonality and tonal gradation in
black-and-white prints. Subject brightness range is interpreted as density
by the film and the the film density range is interpreted by the paper as
shades of gray in the end result. Different combinations of film, film
developer, and paper (FDP) produce different interpretations of the same
scene brightness ranges when the materials translate them as grays on the
paper: thus, with the same film and paper, one developer might tend to
render a middle value a little lighter relative to fixed endpoints, another
a little darker; another might expand highlight values and compress low
values, still another the opposite. The variations are as endless as the FDP
combinations themselves.

Tonality. Tonal properties of materials. The science is called sensitometry
and there is nothing in the slightest subjective about it.

It has nothing to do with your theoretical quasi-scientific maunderings
about the number of shades of gray between white and black. It has to do
with how different sets of photographic materials produce ranges of grays in
the print differently. Some quite markedly differently. Most every
practicing black-and-white photographer knows this happens, or has at least
recognized the practical effects in some vague way. Or were you under the
impression that all sets of materials translate similar subject brightness
ranges to the paper identically?

and then more and more stuff...
<<<<

Wow, these guys really know their stuff!
Thank Gawd I only shoot slide!
Click!
Rob.