Pyro negs in a Jobo Processor

foolscape · Post by **foolscape** » Sat Mar 08, 2008 12:16 am

I want to start developing film with PMK Pyro in a Jobo, but I read that a little ETDA needs to be added. I noticed that there are two types of ETDA: Disodium Salt, and Tetrasodium Salt. Does it matter which one I use?

--Gary

Ornello · Post by **Ornello** » Mon Mar 10, 2008 4:44 pm

foolscape wrote:I want to start developing film with PMK Pyro in a Jobo, but I read that a little ETDA needs to be added. I noticed that there are two types of ETDA: Disodium Salt, and Tetrasodium Salt. Does it matter which one I use?

--Gary

Why are you asking this?

1) Pyro is crappy developer. It's obsolete in any case. You need to use large format film and contact print paper to benefit from it.
2) If you're using pyro, rotary processing is the worst possible choice
3) If you're working with small format, you should not use pyro

twellendorf · Post by **twellendorf** » Wed Mar 12, 2008 6:14 am

I have to agree with Ornello on this one. Pyro had oxidation problems. A Jobo would be the worst possible environment to use pyro.

rwyoung · Post by **rwyoung** » Wed Jun 04, 2008 11:10 am

PMK oxidizes quite quickly. A rotary processor will accelerate the problem.

However, there are Pyro formulations that work fine with rotary processors. such as rollo-pyro and Pyrocat (-HD, -MC).

The stain color with Pyrocat-HD, for example, is not quite the same green/brown as PMK but a more yellow/brown stain. Other differences exist too.

If you really want to use PMK, then consider tray or stand/semi-stand processing.

And pyro based developers work just fine on roll film. However you get larger grain clumps and even with the stain working to "smooth" things over, they can become obtrusive at high magnification.

Pre-mix pyro kits are available and relatively cheap so there is no great harm in trying one. If you like it then you can always go back and fine tune your personal EI and developing procedure.

foolscape · Post by **foolscape** » Sat Jun 07, 2008 3:21 am

Ornello, I shoot mostly LF film, and I wear obsolescence as a badge of honor.

I've been working with PMK pyro for about 2 years. I had been using a dip and dunk system with mostly good results, despite not knowing that I has supposed to be having streaking problems caused by the film hangers. Imagine my surprise when the streaks failed to materialize.

I made a batch of Pyrocat-HD this week, and I'm going to try it on my next batch of film. I'm souring on Pyro developers, though. I rarely get the contrast I like. I processed a roll of Maco ORT25 yesterday in HC110 and got images that I can print on grade 2. Most of my Pyro negs need grade 3 or 4. I may keep Pyro on hand for night photography and for Efke film, which needs a hardeneing developer. I got some Clayton F76+ to process "normal" films. I've used it before.

--Gary

Ornello · Post by **Ornello** » Sat Jun 07, 2008 11:41 am

foolscape wrote:Ornello, I shoot mostly LF film, and I wear obsolescence as a badge of honor.

I've been working with PMK pyro for about 2 years. I had been using a dip and dunk system with mostly good results, despite not knowing that I has supposed to be having streaking problems caused by the film hangers. Imagine my surprise when the streaks failed to materialize.

I made a batch of Pyrocat-HD this week, and I'm going to try it on my next batch of film. I'm souring on Pyro developers, though. I rarely get the contrast I like. I processed a roll of Maco ORT25 yesterday in HC110 and got images that I can print on grade 2. Most of my Pyro negs need grade 3 or 4. I may keep Pyro on hand for night photography and for Efke film, which needs a hardeneing developer. I got some Clayton F76+ to process "normal" films. I've used it before.

--Gary

Pyro negs need to be printed on contact paper such as Azo for maximum effect.