Odd Pyro Negative Problem

Photo Engineer · Dec 8, 2011

UV radiation has more energy than visible light. If a dye is sensitive to UV and is less stable than expected, a dose of UV will cause fading and it can take place more rapidly than exposure to visible light. This has been proven over and over. That is why color paper has a high does of UV absorber in the emulsion layers and in the support.

BTW, was your film exposed base side towards the light or away from the light. I can make some guesses there too.

PE

Crashbox · Dec 9, 2011

This thread has really piqued my curiosity, as I have had a serious affinity for catechol and pyrogallol staining developers for many years now.

I am contemplating the purchase of a UV source and developing some film in my usual stain-o-matic soups, then exposing them to UV for varying periods. Afterwards, I would then compare them to the control neg's cut from the same batch. This should provide some useful information with respect to handling my negatives in the future.

Many thanks to the OP et al. for bringing this to light.

Photo Engineer · Dec 9, 2011

You might want to cover part of the negative for a while during UV exposure to generate the OPs conditions.

PE

Crashbox · Dec 9, 2011

Yep, I was thinking of using something like a coin or maybe even a Post-It-

Photo Engineer · Dec 9, 2011

The coin might be better. We know it is UV proof!

PE

Steve Hamley · Apr 5, 2012

Folks,

Just an update for the forum. I've had the negative laying in a sleeve (like before) next to the same window all winter sans Post-It note, and it looks like the artifact is gone. So is the green pyro stain, now the negative just looks like a regular negative. I'm attaching a scan done today for those interested. Previously, you could barely see the outline of the note in the scaan, but of course it printed more prominently with UV-sensitive media.

My current plan is to try a test print, and if the artifact is truly gone, make a high resolution scan for backup then try to regenerate the stain uniformly using Hutching's metaborate wash or re-fixing in TF-4.

Ideas? Comments?

Cheers, Steve

View attachment 49044

Photo Engineer · Apr 5, 2012

There is another thread going here on the stability of "stained" negatives. This is of great interest in the context of that other thread.

PE

Steve Hamley · Apr 5, 2012

Hi Ron,

When I have a little more info, like whether I can regenerate the stain and after I see if the artifact is gone from a printing standpoint, I'll reference in the other thread.

I think it's important to note that even though the pyro stain may fade under certain conditions, the silver does not and you should still have a printable negative provided you didn't mask the neg like I did. And pyro stain can be removed and regenerated to some extent, Hutchings describes the process in "The Book of Pyro". So I wouldn't worry too much about the archival nature of stain, although printing a given negative without it can be more difficult.

Cheers, Steve

Photo Engineer · Apr 5, 2012

Steve, I agree.

In the other thread though, many seem to think that pyro is stable for a long long time. But, all dyes fade.

Oh, BTW, your reference above fails.

PE

erikg · Apr 5, 2012

Steve, I wonder if you had a chance to look at your negative under a UV (black) light when it had the artifact? I'm curious if anything would be visible under that light, lit directly or by transmission.

k_jupiter · Apr 6, 2012

Never any disrespect to PE, but...
I am 55 YO. No one is going to want to print my negatives after I be dead.
I have found a couple of staining developers that give amazing results for how I shoot.. Pyro cat and W2D2+.
I'll take the short term (only 50 years or so with properly stored negatives) over infinite long term storage than nobody will give a hoot about after I be dead.
And if someone were to pull an Atget, they can scan my negatives and figure out how to preserve them. I don't think there will be an Abbot to save my vision.

tim in san jose

Photo Engineer · Apr 6, 2012

Well, the OP described a situation in which a fresh negative could not be printed due to fade. So......

And, you often have great difficulty printing stained negatives using alternative processes or Azo paper due to the UV vs visible absorption of stained negatives.

But you must do what satisfies you.

PE

k_jupiter · Apr 6, 2012

Photo Engineer said:
Well, the OP described a situation in which a fresh negative could not be printed due to fade. So......

And, you often have great difficulty printing stained negatives using alternative processes or Azo paper due to the UV vs visible absorption of stained negatives.

But you must do what satisfies you.

PE

Of course PE... but he did something pretty.... dumb. No insult to him, he probably didn't know better, but leaving negatives exposed to light isn't the smartest thing to do no matter how they were processed. The fact that he resolved the issue is nice, but we all should agree the negative isn't the same as when he processed it. It has lost information.

As far as pyro negatives being ruined by process light, that's a distinct possibility. Personally, I don't do a lot of reprints, two being a big run for me. I see if someone were going to make a lot of reprints it could become an issue, but holy smokes, most of us print one for us, and a few for friends... maybe. The fact that you can only get that particular look from a particular process (and pyro gives an amazing tonal gradation scale) means you might be reduced to monoprints. Not a detriment in my case, but we all must make that call. I do think the issue is overblown for the majority of us B&W printers. And yes, we must make that call individually.

tim

Steve Hamley · Apr 6, 2012

Photo Engineer said:
And, you often have great difficulty printing stained negatives using alternative processes or Azo paper due to the UV vs visible absorption of stained negatives.PE

I think Edward Weston would probably disagree and has a body of work developed in pyro and printed on silver chloride paper... I've printed many, many, negatives on Azo very well that were developed in pyro.

As far as losing information, I wouldn't call it that. What I've lost at this point is the contrast mask, all the silver is still there. And I can supposedly (according to Hutchings) regenerate at least part of the stain. He notes that you can remove and restore the stain several times and the negative will reach a point where the final stain is somewhat less than a freshly developed negative.

Cheers, Steve

Steve Hamley · Apr 6, 2012

Oh, and it wasn't dumb. Dumb would be doing it twice!

Cheers, Steve

Photo Engineer · Apr 6, 2012

I see no comparison in that print to show me what is going on.

But, I must say that those that print using UV radiation, those that use UV + visible and those that use visible will see differences with stained negative in side by side comparisons.

I object to single examples of this vs that. You cannot do a comparison without both.

Sorry.

PE

Ian Grant · Apr 7, 2012

Steve Hamley said:
I think Edward Weston would probably disagree and has a body of work developed in pyro and printed on silver chloride paper... I've printed many, many, negatives on Azo very well that were developed in pyro.

As far as losing information, I wouldn't call it that. What I've lost at this point is the contrast mask, all the silver is still there. And I can supposedly (according to Hutchings) regenerate at least part of the stain. He notes that you can remove and restore the stain several times and the negative will reach a point where the final stain is somewhat less than a freshly developed negative.

Cheers, Steve

There's two components to stained negatives and this is often overlooked. First there's thestain formed by the inter-action of the developing agent, to quote Kirk Keyes.

Kirk Keyes said:
The stain in Pyro-developed films seems to me to be much more that a "dye". It's actually a chemically bonded cross-linking of gelatin molecules, which happens to have light absorbing properties.

I'm certain the cross-linking can be broken, but it appears the rate with normal storage conditions is not very great. Keep in mind that strong light storage is probably not going to be good for them.
Kirk

This stain is quite different to the general base stain caused by oxidised dveloper, in fact it can be a slightly different colour. When I use IT-8 which is an Ilford Pyrocatechin redevelopment toner the developer will stain the base a bluish colour once oxidised, as will oxidised Pyrocat HD with films. The stain formed by the development process is more typically a reddish brown but this differs in strenght with film types.

The advantage of a stained negative for contact printing and alternative processes is the precisely the way the stain behaves when the light source has a higher UV content, this allows negative to have a dual puropse something that Edward Weston and many others knew over 80 years ago and wrote about in his daybooks. There been a lot of work on this in the past few years particularly by Sandy King.

Ian

Mahler_one · Apr 7, 2012

PE, can you be a bit more specific about your comments? Those less experienced and knowledgeable have thought that one of the advantages promulgated for stained negatives is precisely the ability to use the same negative for Platinum prints AND for printing on Azo papers.

Steve Hamley · Apr 7, 2012

Ron,

Sorry if the tone sounded inappropriate, sometimes print doesn't quite come off like you were sitting with someone and talking. I've looked for a scan of the negative with the artifact intact and can't find it although I think I've mis-filed it somewhere. But the point is you can't see anything and that's WONDERFUL!

Sure pyro stained negatives print differently when there's a UV component to the light, that's the point as Ian writes. The result is more in highlights, like detail in the clouds in the attached image above. Those clouds were difficult; very bright and little detail in actuality standing there looking at them. I would have liked more but that isn't what I had. Pyro (compensating developer) helped preserve what details there were in the clouds and help keep them from becoming paper-white cutouts. I still held them back as much as possible in printing, which I did not do in the scan BTW.

Cheers, Steve

Mahler_one · Apr 7, 2012

What a really interesting and informative discussion from so many viewpoints. Gerald and others: Might you comment again about the possibility that light involved in one's "normal" print making activities could cause fading of the dyes? There were already a few comments on this thread concerning the issue of possible fading of negatives from making multiple prints, and one wonders if such concerns are indeed realistic in the normal course of events. For example: Making 10 prints from a negative developed in PMK, PCHD, ABC Pyro, etc.....would number 10 be any different from number 1? Recall that experts in the use of Azo paper ( e.g., Michael Smith and his wife Paula Chamlee ) recommend a powerful R300 spot light to develop their stained negatives on Lodima and Azo papers. The light source is indeed BRIGHT! I have not read of any problems that either of them have had with making multiple prints from their negatives.

Photo Engineer · Apr 7, 2012

Well, I have seen and heard of people who have printed their stained negatives over and over with great success. Then, they print elsewhere with a different light source and run into problems with exposure! This, I assume, is due to the difference in the ratio of UV to visible light in the printing source. I have printed a number of normal and stained negatives using Azo and Azo type papers. Negatives that look roughly similar by visual inspection (except for the stain) will print very differently on an Azo type paper and it will vary depending on light source.

The yellowish color of the stain or the greenish color of the stain forces the paper to "see" more UV radiation. This portion of the image has a different contrast and density than the visible portion. And, this simple fact is what led me to the comments I made above.

I by no means meant that you cannot get good contact prints with Azo paper. It is just that the results will vary with light source and that the image is not exactly what you see by visible light.

PE

Steve Hamley · Apr 7, 2012

I believe they need that light to print through base fog as reported by someone who has seen their negs -I usually use a 40 or 60 watt bulb at about 2 feet. Remember they're using ancient SuperXX and it was mentioned to me to have appeared to have 2-3 stops of general fog. It isn't the pyro stain as such that's causing the need for an immense light source.

Cheers, Steve

Ian Grant · Apr 7, 2012

There's a been some work done that showed that there's a very slight drop in stain density after intial exposures, this had no effect on the contrast (before or after) and that long term after multiple exposures there was no further reduction in density. In a way this mirrors my comments about there being two types of staining taking place.

If you mix a Staining developer to it's working dilution and leave it (unused) for an hour or so it'll begin to oxidise, with at HD a blue-green colour is formed and if you place a pice of fied B&W paper into it the emulsion and with FB the paper base will be stained blue. If you use fresh Pyrocat as a print developer and later bleach away the silver image you get left with a reddish brown stained image. So two quite different stains which.

Ian

Mahler_one · Apr 7, 2012

I agree Steve. Thanks.

Odd Pyro Negative Problem

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