Re: [APML]: Film

[Jeff Cook <jcook@his.com>]

At 12:28 PM 1/28/98 , you wrote:
>1 - Is there a limit to the length of time, after exposure, that you can
>keep film prior to developing?  If so, what is it?  If there is a limit,
>can it be extended by controlling factors such as temperature or
>humidity?

In dangerously simple terms, exposed film doesn't "keep" as long as
unexposed film. Once the latent image is created in the emulsion, it begins
to change as the film ages. But if the film ages first and THEN a fresh
image is exposed into it, then it is probably going to be a slightly better
picture.  Though you wouldn't likely notice the difference, a fresh image
on spoiled film is better than an old image on spoiled film. 

Either way, film generally belongs in the refrigerator. If you need to keep
it for a long time, before or after exposure, seal it from moisture and pop
it into the freezer. BUT take it out a day or before you need to use it or
room moisture will condense on it and you'll get dew spots. But unless you
are waiting weeks or months in a hot humid climate (or you've bought
late-dated professional film that the STORE keeps in a refrigerator), you
really don't need to worry about rushing your film to the lab.

Also, don't open the plastic film container until you are ready to use the
roll. The air from the factory is drier than the air in your living room,
and you don't want to change that until you have to.


>2 - Since astrophotography consumes a lot of time, several hours per
>shot for deep space exposures, do you normally use full rolls of 24 or
>36 exposure film?  Do you try to shoot the entire roll in one night or

I use both 24 and 36 exposure rolls. Some people "roll their own". Get a
film loader from any good camera shop, reusable canisters and 100 foot
rolls of film. It's a lot of trouble though, and then you REALLY have to
worry about film storage. So I do this: Convince yourself it's okay to
develop an incomplete roll. It's much cheaper than "shooting up the roll"
with junk. Just press the rewind button on the camera (wait until you get
home just in case you witness an alien landing on the way), and take that
sucker in for processing. You get back a fewer prints and a smaller bill.
If you're shooting slides, though, you might as well shoot it up because
you're going to pay for it anyway.


Jeff Cook
jcook@his.com
Washington DC area