Ender100@aol.com
Date: 06/20/03-02:21:16 PM Z
Hi Folks,
Since things have been slow on the list lately, I figured that a few
questions might not choke the bandwidth here.
I am wondering if anyone has done any testing of variations of print density
with say PT/PD caused by different variables. I am doing a research project
with digital negatives and Photoshop curves for various processes and have
run into the issues listed below.
I'd appreciate any input anyone has and information on how much variance in
print density people have found due to these variables:
1. Hot spots in a light source.... either tubes, NUARC, Sunlight, etc. I
would assume Sunlight would be the least. I remember someone posting that
they found very little variance with tubes—even when there was a fair amount
of space between the tubes. How much variance in log density?
2. Hand coating methods. Obviously you could get a lot of variation if
you used a floor mop. So I guess here the question would be better phrased in
the inverse. With an extremely good coating job, how close to zero variance
in log density can you get? .01 log density? .000001 log density? Does
anyone know the standards manufacturers use for silver gelatin paper?
3. I know folks use different methods for smashing the negative down on the
emulsion so it will print sharp—such as printing frames with some sort of
pressure system, vacuum tables, plate glass and boulders, etc. Will a loose
negative affect density of the print at all, or just the sharpness of the print?
4. Speaking of sharpness? I am sure different paper textures and
processes affect sharpness, but how sharp is sharp when printing even the most sharp
of alt processes? How small of a line or patter could one expect to resolve
in a print? One reason I ask this question, is that I have heard people
complain about the "dots" they get with digital negatives. I have looked at a
number of alt prints that don't come close to resolving the dots of a digital
negative—either because of the process or the texture of the paper.
thanks,
Mark Nelson
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