From: Charles Steinmetz (csteinmetz@netexpressway.com)
Date: 01/03/02-09:03:38 PM Z
I've made and coated plates for many years. It's not particularly easy if
you want results
equal to commercial negative materials, although it's not too hard to make
plates that give
recognizeable images.
ISO 125 is a very challenging target, as is panchromatism (or even
orthochromatism).
Blue-sensitive emulsions of ISO 5-10 are hard enough for the beginner. You
*will* need to
sub the plates. You will also work VERY hard to get even coatings that
aren't full of dust
and debris. I strongly suggest looking at Jim Browning's coating machine
plans to see how
it's done right.
There are so many variables (especially the gelatin) that it's almost
pointless to give
specific recipes. Any recipe will take much tinkering before you get it to
work very much
like it worked for the person who gave it to you. My first copy of Baker
was passed down
to me by a Kodak emulsion scientist, and is full of exquisitely detailed
notes. Even so, my
results were very different from his. Until quite recently, emulsions were
tuned by mixing
various lots of gelatin to get the desired speed with a tolerable fog level
(both are strongly
influenced by minute traces of things -- some known, some not -- in the
various gelatins).
Lately, the commercial operators use neutralized gelatin and add the trace
impurities
themselves.
Here is a brief bibliography from my bookshelf (this is an update of a list
I posted some
time ago):
Photographic Emulsion Technique, by T. Thorne Baker
2nd ed. 1948 American Photographic Pub. Co. Boston [1st ed. 1941]
This is the single most useful book I've seen, as far as practical
emulsion-making is concerned. That said, please do not give the
internet photo-book pirate/pimps the >$100 they are asking.
Photographic Emulsions, by E.J. Wall
1929 American Photographic Pub. Co. Boston
The second most useful book. Same comment about pricing.
Photographic Chemistry, vol. 1, by Pierre Glafkides
1958 Fountain Press London
Part II is an excellent general discussion with recipes.
The Photographic Emulsion, by B.H. Carroll, D. Hubbard, & C.M. Kretschman
n.d. Focal Press London & NY
A collection of seminal papers from the late '20s and early '30s. No
instructions for making emulsions, but lots to help you understand and
improve your methods once you are over the beginner's hump.
The Theory of the Photographic Process
1st ed. 1942 Macmillan Co. NY C.E. Kenneth Mees, ed.
2nd ed. 1954 Macmillan Co. NY C.E. Kenneth Mees, ed.
3rd ed. 1966 Macmillan Co. NY C.E. Kenneth Mees & T.H. James, eds.
Very technical compendium of all things silver-gelatin. Again, no
recipes for the beginner, but most all the public-domain information
on silver in one place. In the 1st ed., an excellent discussion of
spectral sensitizing occupies Section VI. It's much attenuated in
the later editions.
C.B. Neblette has a very basic, but good, overview chapter in the
various editions of Photography: Its Materials and Processes (and its
succesor, Neblette's Handbook of Photography and Reprography), and in
Photography: Principles and Practices
Photographic Materials and Processes, by Stroebel/Compton/Current/Zakia
1986 Focal Press Boston & London
A fairly detailed overview chapter. No recipes.
Kodak published a pamphlet with a recipe for slow in-camera film, called
Making a Photographic Emulsion, publication AJ-12 (long out of print,
but sometimes available by calling Kodak's 800 number -- it depends on
the representative you get). Makes a fractional-ISO emulsion.
[I have a set of scans I can send if folks just can't find it]
[I also have scans of 8 pages from another old book, whose title is lost
in the mists of time]
Aristotypes and How to Make Them, by Walter E. Woodbury
1893 Scovill & Adams NY
Paper emulsion recipes, both gelatin and collodion.
Jim Browning has posted his recipes and methods for making dye-transfer
matrix film, from which you can learn a great deal.
Best regards,
Charles (sorry for the spam below)
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