[LargeFormat] Pyro Tips Wanted

[Pete Caluori]

From: Clive Warren <cocam@blueyonder.co.uk>
Date: Fri, 26 Jul 2002 02:57:44 +0100

Have we any Pyro users on the list?

Now that the rubber gloves have arrived am just about ready to begin - are 
pyro users pyronauts?

Anyway, as a relative newbie to this developer it would be great to have any 
tips from more experienced users.

Have trays and the chemicals and will be developing 8x10 film. Does exposure 
need to be modified for pyro development? Will be contact printing and using 
distilled water for the developing stage, tap water for other parts of the 
process.

Thanks for any advice.

Cheers,
        Clive

Greetings Clive,

Pyro is my developer of choice and I use both ABC+ (a.k.a. Rollo Pyro) and 
PMK.  When mixing the sodium metaborate (PMK) be sure to use distilled water 
as this mixture will produce a super saturated solution.  Any impurities in 
the water will prevent the sodium metaborate from being completely absorbed. 
  Be careful with pyro powder and if possible mix it outdoors and be sure to 
wear gloves while processing film.

Generally speaking, you'll see a loss of film speed with Pyro developers.  
It's difficult to overexpose film using this developer, but it's very easy 
to lose the shadows.  Stain characteristics will vary with the film being 
used.  For example, I have found Delta 100 stains very poorly, but HP5+ 
stains excessively.  If you find that stain is excessive, you can control it 
one of two ways.  Add 1/4 teaspoon sodium sulfite to each 1000ml of 
developer, or limit the post bath in either used developer/sodium 
metaborate.  If you use sodium sulfite add it as needed, do not premix.  
Sodium sulfite is stable as a powder, but unstable in solution and will 
change to sodium sulfate and actually increase the stain.

Avoid using an acidic stop bath, plain water works fine and try to use an 
alkaline fixer.  Here in the U.S.A. we can get TF-4 from Photographer's 
Formulary, but I doubt it's practical to ship across the globe.  There are 
formulae for alkaline fixers and I can look them up if you need.

I recommend prewetting your negatives to ensure even development and make 
tray developing easier.  The mixed PMK developer is an alkaline solution and 
simply placing the negs without a prewet may cause them to stick together.  
Believe it or not, the best way to tray develop is to place the negs one at 
a time, emulsion side down into the solutions.  I have found no scratches 
since switching to emulsion side down.  Remove negs from the bottom of the 
stack and place on top.  Rather than sliding negs under the solution, place 
them squarely on top and push them under the solution.  PMK is a soft 
working developer, so be sure to agitate.

I haven't tried PMK in the Jobo (rotary) processor, but I use ABC+ in it all 
the time.  If you're using a rotary processor, I highly recommend ABC+, but 
you can get excessive stain with some films/development times.
Gordon Hutchings' The Book of Pyro is an excellent resource and I highly 
recommend it.
Good luck and let me know if you have any questions.
Cheers, Pete

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