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From: briand@tekig4.UUCP (Brian Diehm)
Newsgroups: net.rec.photo
Subject: Re: Product Quality: Color prints from slides
Message-ID: <334@tekig4.UUCP>
Date: Mon, 21-Oct-85 12:45:00 EDT
Article-I.D.: tekig4.334
Posted: Mon Oct 21 12:45:00 1985
Date-Received: Wed, 23-Oct-85 05:45:17 EDT
References: <298@tekig4.UUCP> <349@vaxwaller.UUCP> <5746@tekecs.UUCP> <1505@utcsri.UUCP>
Reply-To: briand@tekig4Diehm.UUCP (Brian Diehm)
Distribution: net
Organization: Tektronix, Beaverton OR
Lines: 38
Summary: 

>> Reversal color print processes are not as good as negative print
>> processes. MY OPINION: Don't bother to flame if you disagree!
>
>Ever hear of Cibachrome? The results are luminous. Furthermore the
>dye stability is such that it won't fade when hung in a brightly
>lit room. It is ONLY a positive-to-positive process, and VERY
>expensive. Sigh!

Sorry, Cibachrome DOES NOT provide the order of results you are looking for
UNLESS you shoot the original slide with a Ciba print in mind.  This is because
the color saturation and contrast increase inherent in the print process
CANNOT be controlled to match print to slide.  However, if you overexpose the
slide, you wind up with a washed-out slide that makes a pretty good Ciba
print.  It's a no good slide for anything else, though.

Yes, Ciba is permanent - at least it's the most permanent color photographic
process, in theory.

The problem with making prints from slides is that by their nature slides can
contain more information than a print can.  If you compare the range of trans-
mission densities possible through a slide with the reflection density range
possible from any print, the print loses.  The density range on paper, no matter
what the process, is limited to around 2 f-stops, and that's with ideal illumin-
ation and display, while the slide is theoretically unlimited.  Since the
density range of "reality" is quite wide (making metering a process of
judgement), a slide can better match reality.  The limits to the process are
fundamental.

However, that DOES NOT say that Ciba is even close to this ideal.  On paper,
the very best color reproduction is graphics arts 4-color separations, ink on
paper.  Ironically, this process operates best from transparencies!  The best
photographic color reproduction is from negatives, again if the objective is on
paper.  However, if you can get away from paper, transparencies can blow any-
thing else away.  Hence, the frustration of trying to put a slide on paper.
At best, it will always be a compromise.

-Brian Diehm
Tektronix, Inc.