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Subject: Copy negatives

Copy negatives

From: Doug Nishimura <dwnpph>
Date: Thursday, September 5, 1991
Cathy Larson:  With regard to your question about evaluation of copy
negatives from albumen prints, I don't know of any standards. There are
a great many problems that are raised when dealing with evaluation.
Obviously you must be satisfied that there are no coffee stains,
fingerprints, or processing streaks (among other things) on the copy
negatives.  You must also be satisfied that the copy negatives and
prints have been processed for maximum permanence.  Unfortunately ANSI
does not have maximum residual hypo limits for photographic prints in
any of its standards.  The final evaluation should be one of density or
more correctly, of sensitometry. This opens a whole can of worms that no
one really wants to deal with. The evaluation of negatives is perhaps
the worst problem because you can't compare it to an original negative
-- you only have a positive print. You could try to optimize the
negative for the material that you want to print on, but that also can
be problematic.  Historic papers (such as albumen) were of low contrast
but very long tonal range (the visual range from lightest area to
darkest was much longer historically) and therefore if you want to print
on albumen paper, you need a contrasty, loooooooong toned negative.
Contemporary papers have a much shorter tone range and higher contrast
and therefore, if you plan on printing on contemporary paper, your
negative must be lower in contrast and shorter in tonal range.

Whether you get to the print stage or not, there is also the fundamental
problem of how you measure the densities.  Albumen prints are most often
rather warm with yellow highlights and warm blacks.  In good condition,
they may be more purple with fairly white highlights.  Can you measure
the densities purely with visual density or should you be measuring blue
or red density?

I can't say that I have any answers to these problems, but I would
suggest that the next best thing to having standards is to discuss it
with knowledgeable people.  I would recommend contacting Steve Puglia at
the National Archives for one.  His specialty is copying and duplicating
prints and negatives and he has had to deal with the evaluation of
negatives and prints from historic and contemporary (copy) negatives.
He may not have the answer either, but he can certainly provide you with
a great deal of information to think about.  Micheal Hager is also a
useful person to talk to since he also had to deal with these sorts of
problems at the George Eastman House.  I would ask though, if you call
Micheal, to keep calls short.  Micheal now has a private business doing
(excellent) copying and duplication work and for him, time really is
money.  He is very generous with information, but long calls (not
resulting in business) cost him a lot of money.


                  Conservation DistList Instance 5:19
                 Distributed: Sunday, September 8, 1991
                        Message Id: cdl-5-19-002
Received on Thursday, 5 September, 1991

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