> Some astrophotographers I know use gas hypered film which gives them
> an extra couple of stops but I don't know what the gas is. It could be
> ammonia. I do specifically remember reading about supersensitizing film
> by using mercury vapor, I'll see if I can look that one up.
There is a formula in Steve Anchell's, Darkroom Cookbook that sounds
similar to the ammonia method that was mentioned, except that I seem to
remember it using hydrogen peroxide vapors rather than ammonia. I can
look this up tonight. Might be kind of fun to try.
- Wayde
(allen@boulder.nist.gov)