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From: lhdowney@eos.ncsu.edu (Lewis Henry Downey)
Newsgroups: rec.video,rec.photo,sci.electronics,comp.graphics
Subject: Re: Looking for imaging technology experts
Message-ID: <1991Jun12.005735.23619@amd.com>
Date: 11 Jun 91 04:57:05 GMT
Sender: cdr@amd.com (Carl Rigney)
Organization: North Carolina State University
Lines: 37

Don't know if this is useful to you, but I have considerable experience
using trational panchromatic b/w films in low/light (almost no-light)
situations.
 

The resulting expertise is based on techniques of modified film development
and film pre-exposure (as per Ansel Adams recommendations in THE NEGATIVE.
(and obviously on coreections for reciprocity)The technical considerations
 are based as much as possible on determining the relative luminance range 
of the subject. However, I do not have a light meter sensitive enough to get
 reflected reading off of deep shadow areas and am forced to rely on many year 
(and 10's or 100's of hours of logged exposure time) to make certain decisions.

A good rule of thumb is that it is extremely difficult to overexpose
panchromatic film in super low-light situations. Whether any of this
info is applicable to your needs is difficult to say.

Basically, I usually try to create a film density of about .1-.13 in the
area that is intended to be printed black. This allows areas that are slightly
lighter to move up thetoe of the film curve enough to gain more tangible
detail. Of course, each individual situation is accessed on its particular
specifics as well as my subjective intentions for the reproduction.

Recent explorations are leading in the direction of post-exposing the film.

Will be glad to offer any information that is useful to you. The hardest
thing about working at night is focusing.

Warmly,

Lewis Downey
lhdowney@eos.ncsu.edu
Photgraphy Instructor
Meredith College Art Dept.
3800 Hillsborough St. 
Raleigh, NC 27607
919 833-4490 (home with answering machine)