Hi, I recently mixed some Pyrocat HD and developed some HP5+ with it. The film speed was about ASA 160 which is half what I usually rate it at im PMK. Has anyone seen this or perhaps I made a mistake in mixing. Thanks
I can't compare to PMK but EI 160 is exactly what I got for HP5+ in Pyrocat-HD. Other films showed a similar loss. I get EI 320-400 in D-76 1:1.
Pyrocatechin formulas are not known for giving full speed. In most formulations pyrocatechin is used as a compensating developer, generally requiring increased exposure. I've always used an EI of 200 for HP-5+ with both PMK and Pyrocat-HD, but never really cared for the results.