View Full Version : How many 8x10 sheets per 1 Liter of PMK can I do?

4-Sep-2018, 05:54
I see some some stuff on web about 12 sheets of 4x5. Is that about 6 sheets of 8x10?

I see lots of info for 35mm but not really any 8x10.

I have a bunch to do. Thinking of maybe doing 2 Liters in a tray, then I can do like 8-10 sheets? Sounds about right? Maybe I have about 12 sheets not sure...

Fred L
4-Sep-2018, 06:04
12 sheets of 4x5 = 3 sheets 8x10. I've used 1 litre to process 5 sheets in the Jobo 3005 drum and they were fine.

4-Sep-2018, 06:14
Ohhh, only 3?! Okay thanks!! I think that's probably why I got the A+B bottles so I can make them quick. I usually don't have this many sheets to do but having fun with my new pinhole.

I'll play it safe and do 3, not stretching it. Dev is cheap compared to other things.

Drew Wiley
4-Sep-2018, 17:20
Nonsense. You could easily do 8 sheets of 8x10 per liter without risk of exhaustion, provided it's A:B mixed just before use. But that's not the problem with a tray. Rather, how many can you shuffle in a tray without scratching them or getting surge marks? That's why I prefer to do only 3 or 4 sheets of 8X10 at a time in a distinctly oversized 11X14 dimple-bottomed tray. If the particular film prone to excessively perimeter density or surge marks (typically thicker emulsion films), then upping the volume to 2 liters significantly helps. Drums are a different story, and PMK is not the best choice for that application.

5-Sep-2018, 05:38
If you do a small number of sheets at a time, keep in mind that PMK will oxidize and noticeably lose power in <30 minutes. Best to remix some fresh from the A&B concentrates before each batch. If you want to live dangerously you could also just add some each batch to refresh/replenish the mix but that would not be repeatable or based on science.

Miguel Coquis
6-Sep-2018, 12:24

Rick A
8-Sep-2018, 04:17
PMK is a one-shot developer. Because it is so dilute, a minimum of 300 ml of
developer per 80 square inches of film (one roll of 36 exposure 35 mm film, or
four 4 by 5 negatives) must be present in the tank or tray. Inconsistencies can
result by varying the ratio of film to quantity of developer used. Best results will
be obtained by keeping the amount of PMK per roll consistent. "
Copied from the instructions. I personally use 200ml per 4 sheets of 4x5, or 2-5x7's in my rotary drum with consistently good results. Four sheets of 4x5 is equal to one 8x10. Theoretically you can get five sheets per liter at 200ml.

8-Sep-2018, 06:37
Thanks all!! I was thinking of just emptying most out and starting fresh but got lazy and just tipped the tray and most came out, I didn't bother cleaning it. But I did at most 4 sheets per liter. I didn't want to take a chance and besides, those A+B bottles last forever. I think I had about 16 sheets to do so I took a 'cough' 'cough' sick day and did it all in the morning.

I also bought 10x of those surgeon forceps that someone else here explained. That was a brilliant suggestion!