View Full Version : Pyro HD - Sheets per liter

1-Jun-2015, 04:43
Is there a recommended number of sheets per liter of Pyrocat HD at 1:1:100? I only can find minimums for rotary processing. I typically use a tank or trays.

I just ran 8 4x5 sheets through 500ML in a tray over a course of 5 hours and it turned dark by the end, but was still working.

Bruce Barlow
1-Jun-2015, 04:50
I have shuffled10 sheets in a liter with no problem. Yes, it oxidizes and turns dark, even with 10 at a time, but that does not seem to affect the film in the tray. Then I dump it.

Mark Sampson
1-Jun-2015, 11:09
I'd guess that all highly-dilute pyro developers turn dark (oxidize) during processing. At least PMK and pyrocat-HD do, in my experience. Nothing to worry about. I can successfully develop 12 sheets of 4x5 in 1200ml of pyrocat-HD, using a Nikor sheet-film tank. I haven't had to go beyond N+1 but that works too.

1-Jun-2015, 12:28
Seems that rules of thumb abound for most full strength developers:
Minimum 250 ml per 80 square inches 4 x 4x5 or 1 8x10, which works out to 62.5 ml per 4x5 sheet. Mr King mentions a value around 60ml per 4x5 but recommends more for rotary processing. 170-200 ml for roll film 36 exp.

For diluted developers - double it.