PMK Pyro Development

[Pawlowski6132]

I'm going to do a little reaearch on this but, thought I would also start this tread because I always get good facts and opinions that may be useful to others.

Can I use PMK for non-normal developement (e.g., N+1, N-2, etc.)?

I thought I read somewhere that PMK was not fully compatible with Zone System method because of limitations.

Maybe I'm nuts.

[Eric Woodbury]

We're all a little nuts here at LF, but that has little bearing on PMK. PMK will certainly do a broad range of developments. I have used it from N-4 ('abnormal minus') to N+2 with HP5+. It poops out at N+2, in my experience, but there is probably some way to get it to work. If you are going to use this developer or other pyro, you should probably get Gordon's book. Have fun.

[David Hedley]

Contracted and expanded development are definitely possible with PMK Pyro. I tend to use N-1 more than N.

[Pawlowski6132]

Thanx guys. One more question; I intend to use this with a Unicolor uni-directional rotary processor. It's my understanding is that the film develops "poorly" using rotary methods; Urban Myth? Fact? or, somewhere in between depending on individual conditions.

thanx

[Payral]

May be you should read " The Book of Pyro" by Gordon Hutchings. First edition 1992, now it's the third one. A lot about it in different forum. If you make a search you will have a lot of informations and several days of reading.

[Drew Wiley]

PMK is very flexible for Zone system use. But it's not the best choice for rotary development. There are different formulations for that, like Max Pyro, Rollo Pyro, or
perhaps the most popular, some of Sandy King's formulas based upon Pyrocat rather
than pyrogallol. There's plenty of information on the web, or you can find kits for many
of these at Photographer's Formulary, complete with instructions.

[CP Goerz]

PMK is a great developer and I've used it since the book came out on it. N+ development is easier when you add 1/8th Tspn of Amidol to the working solution of developer. If you use PMK for in its straight form it tends to raise all values not just the high end, I've used it in tray and in a Jobo. For rotary development with 120 and 4x5 it works fine but you have to use nitrogen to displace the oxygen otherwise you end up with high fog levels. In 8x10/8x20 and 5x7 etc I tray develop and singly at that as I am one clumsy dude ;-)


N-5 or more is possible by splitting the developer, soak the film in the A solution for half an hour then remove the film, add 1 tbspn of B concentrate to the A mixture you 'hardened' the film in and mix thoroughly, add the sheet back in and gently flip over a few times...you want the film to 'sit' more than be agitated. Remove the film and add another tablespoon of the B solution and mix etc, do this about four times and if you develop by inspection you'll see the image come all the way through to the back of the film. Once you reach the right degree of development fix as usual.


The negative will look a bit thin to the eye BUT will print like a full density negative, I've used this method a few times and though time consuming it does give you an 'escape' when you find that one amazing scene that is too much for a normal minus development method.

[Steve Sherman]

PMK is a great developer and I've used it since the book came out on it. N+ development is easier when you add 1/8th Tspn of Amidol to the working solution of developer. If you use PMK for in its straight form it tends to raise all values not just the high end, I've used it in tray and in a Jobo. For rotary development with 120 and 4x5 it works fine but you have to use nitrogen to displace the oxygen otherwise you end up with high fog levels. In 8x10/8x20 and 5x7 etc I tray develop and singly at that as I am one clumsy dude ;-)


N-5 or more is possible by splitting the developer, soak the film in the A solution for half an hour then remove the film, add 1 tbspn of B concentrate to the A mixture you 'hardened' the film in and mix thoroughly, add the sheet back in and gently flip over a few times...you want the film to 'sit' more than be agitated. Remove the film and add another tablespoon of the B solution and mix etc, do this about four times and if you develop by inspection you'll see the image come all the way through to the back of the film. Once you reach the right degree of development fix as usual.

The negative will look a bit thin to the eye BUT will print like a full density negative, I've used this method a few times and though time consuming it does give you an 'escape' when you find that one amazing scene that is too much for a normal minus development method.

I've used variations on the above for years with great success in some really contrasty situations.

The down side to this particular method is the micro contrast or local contrast suffers quite a bit, the way around that has always been for me to print on a high contrast paper, seems a bit backwards, photographing a very high contrast scene and then turning around and printing many times on a hard contrast paper, nevertheless the end justifies the means as CP indicated very high quality prints are possible.

Another option is Extreme Minimal Agitation development, probably not anymore involved that the above process but this method actually maximizes film speed, compresses highlight contrast and magnifies micro contrast. All things that most B&W printers strive for.

[Drew Wiley]

The problem with tinkering around with amidol in PMK is that you have to have very
consistent and predictable amidol to begin with. It's a powerful developer and a lot
tricker to predict in film dev than in paper dev. Results from one batch of amidol might
not match the next. This chemical is also has pharmaceutical or medical applications,
and ironically, higher quality control is needed for the photographic grade. (Got his info
from someone who marketed amidol and other chem to both).

[Eric Woodbury]

My testing with amidol in a pyro developer, not PMK, show no difference between some fresh white amidol that I recently purchased and some black amidol that I purchase about 30 years ago. Very odd, but that's the truth. YMMV

[Jay DeFehr]

Why not just use a developer that was formulated for use with rotary development? PMK is not even near the top of my list of staining developers, and you'd do better with almost any other. For rotary processing specifically, you should consider one of Sandy King's catechol developers, all of which are compatible with rotary processing, and are available commercially from Photographers Formulary. If you are willing to mix your own, you could use 510-Pyro. It doesn't make sense to struggle with an inferior developer when one has so many better options. If you're stuck with PMK for some reason, the workarounds mentioned above might be worthwhile, if you simply must use rotary processing. In other words, if you have to use PMK, you should use it to its best advantage, which excludes rotary processing. If rotary processing is very important for you, you should choose a better developer. If you must use both PMK AND rotary processing, see the excellent advice above. Whatever you use, have fun!