Comments from the previous article system:
By Jordan - 03:43 PM, 07-08-2005 Rating: None
Claude, this is nice. Are you aware of the informational PDF on the Ilford web site about processing? It provides reliable formulae and times for reversal-processing Pan F and FP4 Plus.
I have a couple of comments on your process:
(1) Instead of re-exposure and re-development, you can substitute a sepia-toning bath. This directly converts the silver halide to silver sulfide, and you get nice warm chocolate-coloured slides. The effect is pleasing with Pan F. With TMAX films the colour is very "orange" due to the crystal phases of the silver halide.
(2) You can substitute sodium bisulfate (not bisulfite) for the sulfuric acid. Sodium bisulfate is a solid that dissolves in water to create the equivalent of sulfuric acid. It is sold cheaply for people who have back-yard pools, as an agent to reduce the pH of the pool (trade name here in Canada and also in the US is "pH Minus". If you need a formula, I can provide it.
(3) I agree with you for the most part about the permanganate. However, the guy behind DR5 (www.dr5.com) has reported some archival problems with permanganate. Also, it must be mixed right before use since it goes bad quickly (dichromate is stable).
I have a summary of B&W slide options here: http://www.photosensitive.ca/BWslides.shtml
By Claude - 05:05 PM, 07-08-2005 Rating: None
thank you for your comments and links, it's allways interesting to exchange informations. I knew the sepia process but .... I do not like the chocolate color
I allways mix my chemicals just before use. What I forgot to say was that permanganate must be strongly mixed. (Even with a magnetic stirrer).