PMK Pyro and 8x10

[David N. VanMeter]

Can anyone tell me how many sheets of 8x10 film I can expect to process in a 1 l iter solution of PMK pyro (tray developing) before it is exhausted? I am reasona bly sure that I have some oomph left after 4 sheets. Also, does it make a differ ence if I process sheets one at a time or 4 at a time considering the second tri p to the developer after fixing for additional staining?

[Lewis Lauring]

I think four 8x10 per liter in trays is about right. I shuffle 8 8x10s at a time 70 degrees for 15 minutes.I think the difference in processing one or four or eight will be in the amount of agitatiion, i.e. the amount of fresh pyro available, which will obviously greatly affect the contrast of the final neg. I try for a contrastier negative for platinum/palladium printing. Sometimes I process at 73 degrees for the same time.Its hard for me to detect much difference.

[Carl Weese]

David,

The 'official' rating is three 8x10's in a liter of PMK, but I don't think you'll have a problem squeaking out four. But they'll have to be all at once. PMK will last through even a long tray development time (20' or more) but should not be used for successive developments, and certainly not if you've put a hypo-laden negative back into the developer for staining.---Carl