Re: I guess I'll do it, too.

[tom@xxxxxxxxxxxxxxxxxxxxxx (Tom Benedict)]

Here's my understanding of why IR film (Kodak HIE, at least) should be
loaded in the dark.  I'm bound to have at least some of this wrong, so
feel free to correct me:

Kodak HIE has no anti-halation backing.  Anti-halation backings are
typically very good absorbers, and keep light from bouncing off the
back of the film and re-exposing the emulsion.  Films without these
backings tend to show halos around bright objects because of this
effect (hence the term anti-halation).

The lack of anti-halation backing means that Kodak HIE works as a
pretty efficient light-pipe.  It's not so much that IR light somehow
goes straight through the light trap on a film can, it's that it can
run up the film and expose it as it goes.  I've played around with
this a little, but haven't done any controlled experimentation.  The
effect is pretty pronounced, though.  It's bad enough that if you
completely over-expose a shot, it can bleed over and kill adjacent
frames on the roll.  (I do mean "completely over-expose".  Going over
a couple of stops won't kill you, but leaving the shutter open for a
minute in bright sunlight will wreak havoc.)

Me, I'm paranoid and hate wasting even a frame from a roll of film
that costs $12 US, so I always load in the dark.  This doesn't mean
you need a darkroom or some elaborate setup in order to do this.
Ansel Adams used to load 8x10 film holders in his sleeping bag by
crawling in head-first.  You can't do this in the field, but my usual
M.O. is to turn off all the room lights, go in a closet, and cram
something under the door.  It's dark enough that I've never had
problems with HIE.

Welcome to the wonderful world of IR photography.  Have fun, and take
more pictures!

Tom

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Topic No. 4