PYRO

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?

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

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.

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.

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http://www.ravenvision.com/peterhughes.htm

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.

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Fred

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!)

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I too am thinking about Pyro and I'd like to use this type of

processor. Any comments?

Rollo Pyro is a modification of the PMK formula that was specifically

designed for tube processing. The formula is available on my site at

http://unblinkingeye.com/Articles/Developers/Formulas/formulas.htm.

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

http://unblinkingeye.com/Articles/Pyrocat/pyrocat.html.