From: Victor Loverro (victor.loverro@verizon.net)
Date: 08/23/02-10:22:04 AM Z
The method I have been using is the one described by Patrick Gainer in an
excellent article in the Mar/April 2000 Photo Techniques titled "More
Pyrotechnics." It is a bleach and redevelopment in PMK process. I have
used it on negatives that were initially developed in non-pyro developers
that were almost too thin for silver printing. I have not done alt-process
printing, but I use the negatives for POP printing on the Centennial paper
which requires a fairly contrasty negative. The negatives also print much
better on regular silver paper.
For the bleach:
2 tsp. potassium ferricyanide
1 tsp. potassium bromide
add to 1 pint of water.
Bleach the negative until there is no more black silver image. This may
be done in normal room light. Wash thoroughly before redevelopment. It is
important to expose the negative to bright light after bleaching and before
redevelopment. Then develop in PMK. I use the normal times recommended for
whatever film I am using. There is no need to fix after and no need to
return to developer. If more contrast/density is needed, the process can be
repeated. One caution: make sure the negative you use is thoroughly fixed
and thouroghly cleared of any fixer. Any residual fixer may cause streaking
in the redeveloped negative.
----- Original Message -----
From: "Carl Weese" <cweese@earthlink.net>
To: "altphotolist" <alt-photo-process-l@sask.usask.ca>
Sent: Friday, August 23, 2002 9:09 AM
Subject: negative intensification
> Many alternate processes require negatives with more contrast than
"normal".
> Some films can easily reach the needed level of contrast simply by
extending
> development, others do not respond as well. Intensification to increase
> contrast is another way to get long scale negatives. I'm interested to
know
> if anyone on the list uses this approach routinely, or as a normal
> corrective procedure. If so, what methods have proved most useful?
Selenium
> looks like the simplest procedure, but there are others and I'm curious
> about results.---Carl
> --
> web site with picture galleries
> and workshop information at:
>
> http://home.earthlink.net/~cweese/
>
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