RE:Silver sensitization w/ NH3?

Jason Revell (jason.revell@unn.ac.uk)
Wed, 25 Sep 96 14:56:00 PDT

> I was talking with my martial arts professor recently, and he noticed that
> I'd stashed several boxes of 4x5 in the fridge. The conversation turned to
> photo-related topics, as he had done some press coverage in the 50s/60s.
>
I use a Ammonia solution to hypersensatise film were I work. This is
needed for what I can only really call a TRUE alternative process. This
process, called the Russel effect, records auto-oxidation of paper's,
oil's,
varnishes and paint's. The image is formed by the oxygen given off by
these substances rather than light! This involves a reasonably long
exposure ( 2-4 days, sometimes a month!) even after hypersensitising the
film.

I use a solution of 1000ml pure water to which is added 5mls of Ammonia
(0.880). The film, lith film in this case (Kodak LPF7, 10x8 inch), is then
submerged in the solution for 3 minutes and then left to dry. Afterwards
the
film is processed as normal. All this work has been carried out in total
darkness, though I intend to test a safelight in the near future (One has
only
just arrived). I have found that this increases the film speed noticeably
but by
how much I am not sure, though I would guess about 2-4 stops. This
generally works quite well but the film is VERY sensitive to handling after
hypersensatisation, and it must be used with in a few days, or the film
fogs.

I also have references to a few old recipes from a Dictionary of
Photography from 1951 where it gives various methods using Ammonia
(approx +1 stop), Mercury vapour (inconsistent) and Sulphur Dioxide (+1-2
stops). Please contact me if you would like the details, though I should
point
out I have never used any of these. I also seem to remember one using
Formaldehyde but I can not remember from where.

Jason Revell

<jason.revell@unn.ac.uk>