Stain appearance on Pyrocat-HD?
Hi- searched for info but didn't find anything among the myriad threads about Pyrocat, so bear with me:
Just developed my first roll of 120 in Pyrocat-HD. It was Tri-x (400), exposed at iso 320; I developed for 12 min at 74 degrees (just a SWAG to start off...) using reduced agitation per Sandy King's article (1st min, 10 sec at the end of every 3 minutes thereafter.) Began with a pre-soak while I mixed the developer, and fixed with fresh TF-4 for 5 minutes. And developer and fixer were mixed using distilled water; tap water used for everything else wet, including final wash.
My negs actually look quite good for a first try...sharpness seems really nice and I'm sure I can get good prints once my darkroom is set up. Obviously, some fine-tuning is in order but I seem to have gotten it somewhat right.
Still, the negs have a uniformly purplish look, pretty much like tri-x souped in D76, HC110 or Xtol--I don't see any of the staining that Pyrocat is supposed to bring. How obvious should the stain be on wet negs?
Did I overfix and eliminate the stain? Is the film base color hiding it? Did I do something else wrong? Is everything OK, and I just don't know what I'm looking for?
Thanks for the sage advice...
In my experience, Pyrocat-HD doesn't stain as much as it tans the emulsion. The stain it does leave is a purplish brown, and prints extremely well. Good luck and hurry up and get your DR up and runing so you can get printing.
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Thanks for the info...if it's purplish-brown, maybe it's hidden by the base color?
Alas, won't have a darkroom until at least December, more likely January...have a slim chance to access a community darkroom in Sept/Oct.
Developing negs in the bathroom of a rented house at the moment...don't even have my scanner with me. Shoulda packed that into my luggage.
There shouldn't be any purple. How long did you fix it? You need to fix it long enough for the magenta to go away. The Pyrocat HD stain is brown and constitutes a greater % of the image than with other pyro developers such as PMK or ABC. So if your problem is not enough stain, something is wrong. Too much sulfite in the A solution will destroy stain. Maybe that's your problem.
Solution was Formulary purchased, and all the tri-x I've ever shot has retained a purplish tinge, unlike say Efke that's on a clear base. I fixed for 5 min in TF-4; I was actually worried I'd over-fixed as the directions say 3-4 minutes...
Presoak always comes out loaded with dye, of course--didn't think there was much else to remove. But tri-x should look completely colorless after processing??
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No, it's perfectly normal that there is a little residual magenta dye in Kodak BW films after processing. This is addressed in Kodak film data sheets, and it's maybe the most frequently asked question here. It is supposed to be there, however, you can wash it all away by using extended fixer time, HCA and loooong wash, but you really don't need to.
Sounds like all the tri-x I've processed over the years, then. But should this coloring hide the pyro stain, or should it be obvious to look at? And if so, where could I have gone wrong with the development?
Now that the film is dry, I can see the unexposed areas don't seem completely transparent--a bit hazy, perhaps. Is this base stain? Is it normal or a symptom of something gone awry?
Last edited by AgentX; 08-22-2010 at 08:03 AM. Click to view previous post history.
OK, morning's arrival was a big help--now that I have some real light, I can see the image appears to have a browner tinge in areas of density than I'm used to with non-staining developers, so I guess that's it!
You should see only the stain color. The edges and shadow areas should be clear except for base fog, which should be virtually invisible. N+ development will of course increase base fog.
Originally Posted by AgentX
The dye that comes out in the presoak is anti-halation dye and is not what you're seeing after fixing. That color comes from sensitization dye which only comes out through fixing. I don't use Tri-X so I have no good benchmarks for how long you should fix them, but I have fixed my 400TMax negatives for as long as 20 minutes before the damned magenta was all gone. Didn't hurt the negatives a bit. Tri-X fixes much faster than TMax, but I should think 10 minutes in the fixer wouldn't hurt a thing. Try that on a test negative.
You DON'T need to clear all of the magenta dye, and it is NOT a sign of bad fixing if it's only slight as it usually is. There are proper fixing result tests (residual halide tests) available.
Originally Posted by c6h6o3
Slight magenta cast won't affect the printing in practice. You can also put the negatives in bright light for a few days, the dye fades away.
Please see KODAK recommendations for magenta dye and fixing; http://www.kodak.com/global/en/profe...4043/f4043.pdf page 5 (TMAX).