That makes sense. This test was done with Ilford MGIV-RC, which, being paper, has a fine-grain emulsion.
Regards Ralph W. Lambrecht http://www.darkroomagic.comThis electronic message contains information that is confidential, legally privileged or otherwise protected from disclosure. This information is intended for the use of the addressee only. If you are not the intended recipient, you are hereby notified that any disclosure, copying, distribution, printing or any other use of, or any action in reliance on, the contents of this electronic message is strictly prohibited. If you have received this communication in error, please notify the sender and destroy the original message immediately.
P don't print this e-mail unless you really have to On Dec 21, 2009, at 22:57, Richard Knoppow wrote:
----- Original Message ----- From: "Ralph W. Lambrecht" <info@xxxxxxxxxxxxxxxx >To: <pure-silver@xxxxxxxxxxxxx> Sent: Monday, December 21, 2009 7:25 AM Subject: [pure-silver] Re: BleachThis is very interesting, I think its the first quantitative data I've seen on the effect. The rate of bleaching is probably affected by the nature of the emulsion; fine grain emulsions being bleached faster than coarser grained ones. That means that paper will be, in general, more vulnerable than film, and that warm toned paper will be bleached more than cold tone paper. FWIW, Kodak recommends film strength rapid fixer with the addition of about 15grams per liter of citric acid as a mild bleach for removing dichroic fog. The citric acid is specifically a sequestering agent as well as lowering the pH slightly. Even sodium thiosulfate fixer will bleach but is much slower.Alan Look at these results from a film-strength acid fixer test:-- Richard Knoppow Los Angeles, CA, USA dickburk@xxxxxxxxxxxxx= = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = ====================================================================== To unsubscribe from this list, go to www.freelists.org and logon to your account (the same e-mail address and password you set-up when you subscribed,) and unsubscribe from there.
