Pyro Developers and Dual Purpose Negs

[Richard K.]

I've used PMK to make negs that are reasonably good for both silver and Pt processes and am wondering if the same applies to Pyrocat HD? Do you fine tune depending on destined process? If so, how do you adjust ISO and developing time? Thank you...

[David Schaller]

I use Pyrocat HD for both processes, except when I have extreme subject brightness range. Then I think it's best to make a choice. For example, I was taking some shots in a dark church with bright stained glass windows, that would be N-7 or N-8, for which I used very dilute D-76 and minimum agitation. But for most pictures, to N-4 or so, I've used Pyrocat and have been able to print easily in either silver or Pt/Pd. It would be worth testing yourself to get your own EI for different films, but with Pyrocat, I shoot HP5+ at 250 or 300, whereas I would rate it at 200 for D-76. The same is true for FP4, I rate it at 64 for D-76, but at 100 or 125 with Pyrocat. So I have to choose. With Acros, on the other hand, I rate it at 80 for either Pyrocat or D-76.
Dave

[Richard K.]

Very helpful, thanks Dave!

[D. Bryant]

Very helpful, thanks Dave!

Pyrocat HD is a superior developer for iron based alt. processes and dichromated colloids such as carbon and gum.

TMAX 400 performs wonderfully. Take a read of Clay Harmon's article on The Unblinking Eye for some good hard information.

[Andrew O'Neill]

I have been able to print the same negative on silver VC papers and kallitype using HP5 and pyrocat-hd. I kept everything the same (EI, dilution, dev time), and adjusted the restrainer for more contrast when making a kallitype print. HP5 and pyrocat-hd stinks though, for carbon printing. Use a high contrast developer like D-19 1+3.