PYRO : LUSENET : Large format photography : One Thread

In "The book of Pyro" the author suggests that PMK developer isn't suited for deep tanks and steel film hangers, however the "Darkroom cookbok" says that it can yeild excellent results. I am a 8X10 photographer (amateur) who would like to try Pyro development, but I like using tanks and hangers (20 negs at a time) for the convenience. Anybody have ideas?

-- (, May 01, 2000


I've been using PMK exclusively for a while now, and I am still getting to grips with what is undoubtedly an amazing developer. I have only recently had a problem (involving uneven development) as a result of filling a tank with too much dev. I was using 120 rollfilm in a Paterson Universal Tank. I am confident that I have rectified the problem!!. IMHO I think that Gordon Hutchings is suggesting that using a deep tank for 10x8 may result in difficulty with the rigorous agitation required of PMK. All that I can suggest is that you try developing a few trial sheets of 10x8 with fairly rigorous agitation to ensure even coverage. When I use PMK with 5x4 sheets I invert the tank ( a Combi Plan) twice every 15 seconds, I would imagine that you may find that you are agitating the tank even more, and possibly even continually!! If you get it right however, you will see what all the fuss is about PMK!! Best of Luck Paul

-- Paul Owen (, May 01, 2000.

I have also had uneven development problems developing 120 with a Paterson Universal tank using D-76 1:1, so your problem may not have been the pyro. I prefer stainless, but somehow in a move somewhere I got separated from my 120 stainless steel reels. I just tossed the Paterson tank, which I only kept as a spare, got new 120 reels and switched back to stainless.

-- David Goldfarb (, May 01, 2000.

A deep tank uses solution inefficiently, hence is only economical for replentished developers, not one-shots like PMK. A deep tank for 8x10 takes 3.5 gallons (14 liters)! I develop 8x10 in trays.

-- Peter Hughes (, May 01, 2000.

Its been awhile since I read Hutching's book on the hanger question...I think the point was that traditional stainless hangers have holes which will create strong current effects on the bottom edges(uneven development) using traditional lift/tilt type agitation. He does reference a type of hanger that I've never seen...don't recall the name, as being possible if one is committed to tank processing. I've had nice luck with 4x5 and 8x10 in trays with PMK. Certainly the volume of developer is more efficiently used in a tray.


-- Fred Leif (, May 01, 2000.

What about using a rotary processor? I have and use a Unicolor roller with Rodinal 1:25, and have had great success with my vast amount of 8X10 film shot and processed (9 sheets now!)

I too am thinking about Pyro and I'd like to use this type of processor. Any comments?

-- David Grandy (, May 02, 2000.

Rollo Pyro is a modification of the PMK formula that was specifically designed for tube processing. The formula is available on my site at Also, Sandy King has come up with a pyrocatechin formula, which he calls Pyrocat-HD, that produces similar results to PMK but is less toxic and doesn't have problems with uneven development--I think it would be perfect for deep tanks or tube processors. Further information on Pyrocat is available at

-- Ed Buffaloe (, May 03, 2000.

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