Pyro Developer : LUSENET : Large format photography : One Thread

I,m considering trying Gordon Hutchings' PMK pyro formula for negative developer. I would like to hear of any experiences--good or bad--that others may have had with this formula.

Thanks, Kent

-- Kent McClelland (JuKeMa2@aol.c0m), May 10, 1998


Kent, I've been using the PMK formula for some time, in all formats, and have had very positive results.

If you don't already have Hutchins' Book of Pyro, by all means get it. It's very comprehensive, well written, and will pretty much answer any questions you may have about PMK, not only about developing film in PMK, but about proper exposure, printing, safe handling, etc.

Sooner or later, everyone brings up the extreme toxicity of pyro. Hutchins states that pyrogallol is the most toxic chemical one can use in the darkroom. Mixing the stock solutions from the dry powder, and possibly inhaling the dust, is potentially quite dangerous. The new, pre-mixed liquid PMK solutions should solve that potential problem. Also, handling of the stock solutions during development, particularly with LF films in open trays, should always be done using rubber gloves, tongs, etc. Of course, common sense is the rule.

I find PMK superior to other developers in many ways. This is most evident in the excellent separation in the higher values. PMK negatives reveal distinct and subtle nuances within these densities. Also, the staining characteristics of pyro yield negatives with less pronounced grain, even with fast films like TRI-x and HP-5. Print tonality also appears smoother, more "liquid", when photographing certain types of atmospheric conditions. But then, these are very subjective qualities that one has to experience firsthand.

Properly measuring negative densities can be a bit tricky at first. Initially, the yellowish-green negative stain of the PMK pyro developer tended to throw off my densitometer readings. This colored stain acts as a filter, preventing accurate density measurements. I've gotten pretty good at judging proper development and resulting densities by eye, particularly with sheet films.

I have not had good results with the Tmax films. I'm sure others have had positive results with these films, and can provide different opinions. My best results have been with the Ilford films, particularly FP4+ and HP5, in 120, 4x5 and 8x10, and Pan-F 50 in 35mm. Tri-X is good too, in all formats.

It is the most economical developer I've ever used. The stock solutions keep forever. Hutchins reports PMK does not work well with the rotary (roller-drum) development processes, like the Jobo units. The reasons for this are rather technical, so I would direct you to his book. It does work very well with tray development and LF films, and also with 35mm and 120 in daylight tanks.

Give it a try, and draw your own conclusions. If you have any specific questions, please post a follow up or e-mail me directly.

Good luck , Sergio.

-- Sergio Ortega (, May 11, 1998.

I've been using Pyro as my developer of choice over the last the last six years with 35mm, 2 1/4, and with 4X5 and have been extremely pleased with the results. I normally shoot Ilford FP4, HP5 and sometimes Konica infrared.

Get PMK in solution from rather than the powdered form, and get a hold of Gordons Hutchings book on PMK.

-- John Webb (, May 12, 1998.

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