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From: ron@brl-sem.ARPA (Ron Natalie )
Newsgroups: net.rec.photo
Subject: Re: Re: Product Quality: Color prints from slides (contrast buildup)
Message-ID: <468@brl-sem.ARPA>
Date: Thu, 31-Oct-85 15:54:14 EST
Article-I.D.: brl-sem.468
Posted: Thu Oct 31 15:54:14 1985
Date-Received: Sun, 3-Nov-85 10:37:44 EST
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> The contrast range of a medium basically is the difference between its 
> blackest black and its whitest white.  Actual scenes can have an apparent
> range of over 10 f-stops; the greatest range typically available on B&W
> paper is about 7 stops.

I disagree with this simplistic view.  The black and white intensities
are not what determines contrast, but the number of distinguishable
intensities.  Take it as sort of a visual S/N ratio.  Both grade 1
paper and Kodalith have the exact same white and black values, but
you can see more shades of grey on the lower contrast paper. I'm don't
think f-stops are a valid unit here. Actual scenes is a misnomer here as
well.  What you are really saying is the human eye has a much greater
contrast range than any film does.