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Pyro without stain

Edward Weston's negatives are still being printed today and they are all Pyro negatives, I doubt many other peoples negatives get printed as much. So I think the stain fading issue isn't a worry.

I think we may be over-looking something Hydroquinone is used as the sole developing agent in some older warmtone paper developers, the warmer the tone the finer the grain, Pyrocatechin on its own is also used in fine grain film developer. Now I've never seen a fine grain film developer with just Hydroquinone (it's only used on it's own in high contrast film developers), it's not as active as Pyrogallol or Pyrocatechin.

But at the dilutions of say D177 how grainy will the results be from Pyrogallol on it's own, Kodak give two dilutions one works out at 0.91gm/litre Pyrogallol the other for softer negatives 0.45g/l.

Ian
 
I don't know too much about the chemistry part, but I've used Pyro PMK and I think there's an advantage with the stain. In the highlight areas where the green stain is more dominant, it actually lowers the contrast with multigrade paper so the highlights print easier. Correct me if I'm wrong. I noticed that snow prints with better texture.
 

I don't use PMK but it's similar with PyrocatHD, it's amazing just how easy the negatives are to print, they scan just as well too. I've not used Pyrocat HDS for that long only about 12 years but so far it's proved better with every film and lighting situation that I've encountered in the previous 38+ years

Ian
 
One of the reasons to use pyro is the advantages of staining, so why would one want to use pyro and remove or eliminate the standing. Sandy King need not reply.
 
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Raghu Kuvempunagar said:
This is very useful information. Thanks. Was this for a specific film or generally applicable for all films?
Click to expand...

You'd have to check the citation, which I have not. Whatever the answer, that film isn't available 90 years later. But the relative proportions should still be uh...relative.
 
In his "Introduction to pyro staining developers" Sandy King mentions that pyro deteriorates rapidly in solutions with high sulfite content so something like D76 with HQ replaced by pyro might work but would likely be less stable.
 
From a really old thread:
https://www.photrio.com/forum/threads/im-suffering-from-gainer-illiteracy.3886/print

Patrick Gainer: "You would find that Pyrocat HD with enough sulfite would give no stain. Pyrogallol will also be stainless with enough sulfite. More and more sulfite is required as you go from one to another of those. The tanning action is more difficult to get rid of."

The last sentence is quite interesting as it seems to suggest that tanning can happen even when sulfite is present.
 

Another old thread:
https://www.photrio.com/forum/threads/superadditivity-of-metol-and-catechol.47196/

Sandy King: "You will also reduce the stain of Pyrocat-HD by adding too much phenidone, or by adding too much sulfite, or by adding too much ascorbic. Some people might want to do this since you get the tanning without the stain."
 
I think Patrick Gainer was right Tanning and Staining don't always go hand in hand. The problem is as Gerald Koch has mentioned most modern films are well hardened so there's less effect with a tanning developer, there will be exceptions Acros has poor hardening, as did the older Tmax 400 (not as soft as Acros though), all EFKE films had soft emulsions and Foma films are (and papers) are less well hardened.

Ian
 
I think of Rhubarb when I use Pyro .. the tannin effect tightens around the bloomin silver just as my mouth tightens when I eat the stuff raw.
 
Couldn't resist... Gordon Hutchings mentions rhubarb in his great book.
 
The chemistry of pyrogallol is probably similar to that of hydroquinone, which has an oxidation product that is a developing agent. Neither is likely to be as sharp as Xtol where the oxidation product is an inhibitor of development.Here I refer to development in non-staining/tanning sulfite solution. But pyro might be preferred for tonality, IDK.
 
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