Re: Trick for increasing speed of photo papers?

I seem to recall that you place a tray of strong ammonia at the bottom of a
box and hang the film at the top of the box. I'm not sure what the
recommended time would be--maybe 20 minutes to an hour. I've also heard of
placing a roll of film in a large tank on top of several empty reels with a
few ounces of strong ammonia at the bottom for up to 24 hours. Disclaimer:
I have never tried this myself. In trying to research hypersensitization by
fuming, I found only information on hypersensitizing albumen paper with
ammonia. Clerc mentions hypersensitizing film by fuming with mercury, but
not ammonia. I suspect if this were a really useful method, a lot more
people would be doing it.

----- Original Message -----
From: "Gordon J. Holtslander" <holtsg@duke.usask.ca>
To: <alt-photo-process-l@sask.usask.ca>
Sent: Thursday, November 18, 2004 9:23 AM
Subject: Re: Trick for increasing speed of photo papers?

> Ed:
>
> Do you have more information on fuming film with ammonia? I'm planning on
> doing more work with pinhole cameras. I use lith film which is pretty
> slow. I've managed to squeeze more speed out of these films, but I
> haven't tried ammonia fuming.
>
> Gord
>
> On Wed, 17 Nov 2004, Ed Buffaloe wrote:
>
>> The only thing I can think of is fuming with ammonia. I know this trick
>> was
>> used with albumen, and later with film.
>>
>> ----- Original Message -----
>> > Is there any trick that can be used to increase the sensivity of B&W
>> > photographic paper (by say... 2 or 3 stops for instance)
>> >
>> > TIA,
>> > Loris.
>>
>
> ---------------------------------------------------------
> Gordon J. Holtslander Dept. of Biology
> holtsg@duke.usask.ca 112 Science Place
> http://duke.usask.ca/~holtsg University of Saskatchewan
> Tel (306) 966-4433 Saskatoon, Saskatchewan
> Fax (306) 966-4461 Canada S7N 5E2
> ---------------------------------------------------------
>
>
Received on Thu Nov 18 10:47:01 2004