From: Judy Seigel (jseigel@panix.com)
Date: 05/09/00-06:48:59 PM Z
On Tue, 9 May 2000, Richard Knoppow wrote:
> >
> >So Chris, depending on how soon you're going & how generous your tolerance
> >is, you probably could run a test now of a gray scale, & develop .... at
> >whatever intervals seem likely, to allow for duration of the trip. It's
> >even possible you might get a handle on change of exposure or development
> >as the trip progresses...
> Processing should also be done quickly since the contrast drift will
> continue after exposure plus the latent image will change. Again, this is
> not an issue for B&W so refrigerated storage is not important for this
> reason although it may improve storage life.
> Latent image stability has been the subject of extensive research. Its
> important for both B&W and color films but especially for color as detailed
> above. Modern film is very stable. However, the latent image will tend to
> become degraded with time plus there is the usual fogging of the unexposed
> halide from cosmic rays and chemical changes.
Actually, I was conflating two topics -- difference between roll & sheet,
and changes after exposure.
As I recall, there are changes after exposure not related to "shelf life"
pre-exposure... enough for instance for David Vestal to use
"latensification" as a method of "harmonizing." However these may be
relatively minor in the grand scheme of things, & immaterial for our
(Chris's) purposes. Still, planning a trip with lots of important pictures
& expensive sheet film -- it might make sense to advance test. (I mean
enough stuff is going to happen you didn't think of.)
Judy
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