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View Full Version : Pyrocat - how many 8x10 sheets per batch?



Tony Karnezis
4-Nov-2004, 11:35
I just started shooting 8x10. In my trial darkroom runs, I can handle 4-8 sheets of 8x10 film in one liter of pyrocat HD in 10x12" trays. How many rounds can I use the pyrocat before mixing a new batch? If the developer can be reused for a second round, should I do my N+ negs first and then do the N- negs in the second round? Or is the developer good for a fixed number of 8x10 sheets (ie. good for a given surface area of film) regardless of how many rounds of development I do with a given batch of developer? I don't plan on changing from pyrocat, but does the answer to my question vary with different pyro formulations--specifically ABC pyro?

Regarding my materials and intentions, my trials have been with HP5+. I just bought a batch of Efke PL100 which will likely be my primary film. I will likely use JandC 400 instead of HP5 as a higher speed film. I will develop multiple sheets in trays at 2:2:100 for contact printing on Azo.

If I have missed the thread with the answer, please pardon the repeat question and just supply me the link. I don't mean to waste anyone's time. I simply haven't found the answer on this forum or Michael and Paula's Azo forum. Many thanks in advance.

Jim_3565
4-Nov-2004, 17:19
Limit it to four 8 x 10 sheets/liter at the 1:1:50 concentration and you can't go wrong. Since the film costs me > $3.00/sheet, why quibble over pennies?

Tony Karnezis
4-Nov-2004, 17:36
I'm not trying to skimp at all. To the contrary, I've been mixing a new batch of developer every 4-8 sheets, depending how many I have at hand to develop, because I don't want to compromise. If , however, someone said I could develop 50 sheets of film in one liter, why would I want to dump all that good developer into the sewer system?

sanking
4-Nov-2004, 17:38
Pyrocat-HD was designed to be used as a one-shot developer, using a minimum of about 100 ml of developer per 4X5" sheet of film, or about 400 ml for a sheet of 8X10" film.

Assuming that you developed five sheets of 8X10" film using 2000 ml of developer, and then ran a second batch of five sheets through the same soup, the second batch would have slightly lower contrast and some additional B+F from oxidation. In other words, you should not use this method of development if you want to maintain consistent in your negatives. My experience with other pyro developers, including PMK, Rollo Pyro and ABC Pyro, is that the results from a second batch through the same developer would be even less acceptable because all of these developers oxidize more rapidly than Pyrocat.

Andre Noble
4-Nov-2004, 17:49
Use it on a 'one shot basis' and based on info (from I believe the instructions or perhaps S. King himself????), I have it in my notes to use:

At least 200ml of the 1:1:100 working solution per 8x10 area of film.

Therefore perhaps at the 2:2:100 you can use it 'one shot' with a minimum of 100ml of working solution per 8x10 area of film.

Tony Karnezis
4-Nov-2004, 19:10
I'll keep on doing what I've been doing. Thanks to all of you, especially Sandy King, for sharing so much useful information.