"Francis A. Miniter" wrote in
message ...
Gilbert wrote:

Has anyone found a way of not doing this in complete
darkness, eg. night-vision, infra-red or special
safelight filter?


Yes. Look at this thread :
http://www.apug.org/forums/showthrea...night+vi sion
snip

Gilbert


The only light that I have heard to be safe during
development of panchromatic is in the following situation.
When developing sheet film (don't try this with 35 mm
film, it is too small to inspect properly), after the film
has been in the developer bath for about 3/4 of the
allotted time, you may hold it up briefly in front of a
dim, dark green safelight for purposes of inspection of
the degree of contrast obtained.

Francis A. Miniter

This is based on the fact that the dark adapted eye is
most sensitive to blue-green light so the light can be the
dimmest possible. Also, most panchromatic dyes have a dip at
about the same color, some modern films, like T-Max, do not.
The use of the light during development also counts on the
fact that the emulsion is substantially desensitized by the
development process. Nonetheless only very weak light can be
used for a few seconds without danger of fog. That's why
Kodak wants you to wait until development is three quarters
done.
I believe that IR light with IR goggles are used in some
film manufacturing plants, mainly for trouble shooting. Most
panchromatic films have little or no IR sensitivity. This is
really not practical for home use.
The first film I ever developed, some 55 years ago, was
orthochromatic, probably the old Verichrome. It was done
under a "ruby lamp" a small red light bulb. Those starting
out now will never know the thrill of seeing the image come
up on the film (it seemed to take forever) because there is
little ortho film made now.


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Richard Knoppow
Los Angeles, CA, USA