Pyro without stain

Raghu Kuvempunagar · Feb 11, 2018

I've heard that Pyro stain can fade if the negatives are exposed to a lot of light and/or not stored very carefully. So considering Pyro developer that doesn't stain.

1. How much sulfite should be added to a Pyro developer working solution to prevent stain?
2. Does sulfite addition affect tanning of the negative? Is it possible to get tanning effect without stain?
3. What are the advantages/disadvantages of Pyro developer that doesn't stain?

trendland · Feb 11, 2018

Raghu Kuvempunagar said:
I've heard that Pyro stain can fade if the negatives are exposed to a lot of light and/or not stored very carefully. So considering Pyro developer that doesn't stain.

1. How much sulfite should be added to a Pyro developer working solution to prevent stain?
2. Does sulfite addition affect tanning of the negative? Is it possible to get tanning effect without stain?
3. What are the advantages/disadvantages of Pyro developer that doesn't stain?

As far as I know there is no pyro without stain. It is THE Spezial characteristic of pyro developers.
But that might be not corect. So lets hear what others have to state about pyro developers without stain.
with regards

Gerald C Koch · Feb 11, 2018

If the sulfite concentration is similar to that of nonstaining developers then pyrogallol behaves similar to metol. Which also implies that there is no particular excuse for using it. Pyrogallol was used for a long time before its staining feature was known. IIRC it is the oldest developing agent. Mathew Brady used it so it goes back to the 1860's.

If there is no staining then there is no hardening.

NedL · Feb 11, 2018

Even before the 1860's it was used to develop calotypes in the 1850's, and also to develop albumen plates.
Gallic acid preceded it, going back to the 1840's, but it might not be a "developing agent' in the way Jerry means.

Ian Grant · Feb 11, 2018

There were non staining Pyrogallol developers made and sold commercially I have the formulae somewhere, and both Ilford and Kodak used Pyrogallol in MQ commercial D&P developers as an oxygen scavenger.

Kodak D177 is a Pyro-Soda dish developer with Sulphite that Kodak Ltd sold as a powder packaged developer, it has 50g Sodium Sulphite (anhyd) to 12.5g Pyrogallol. I think the idea is just enough Sulphite to prevent the stain but not enough to prevent the tanning and edge effects. I have a 1939 Kodak Ltd Professional catalogue that should list it, it's in my darkroom (at the end of my garden) I'll look and see tomorrow.

D177 was one of a series of Kodak Ltd developers not made or sold by Eastman Kodak.

Ian

Bob Carnie · Feb 11, 2018

I tried PMK without the stain early in my testing and from what I remember there seemed to be a noticeable visual appearance of grain in the prints vs stained negs.

Ian Grant · Feb 11, 2018

Bob Carnie said:
I tried PMK without the stain early in my testing and from what I remember there seemed to be a noticeable visual appearance of grain in the prints vs stained negs.

The stain is supposed to diffuse slightly and fill gaps between the grains helping reduce the apparent graininess when printing the negative. I push processed some5x4 HP5 to 1600 possibly faster 18 months ago and was very surprised at the grain which hadn't increased like I'd expected = I put that down to the significant increase in staining.

Ian

Bob Carnie · Feb 11, 2018

Makes sense, long time ago but the memory of increased grain stuck with me ever since.

Gerald C Koch · Feb 11, 2018

Gallic acid will function as a developing agent. When heated it forms pyrogallol hence the name.

Gerald C Koch · Feb 11, 2018

Of course we still have not addressed the question in the OP since the image is redeveloped in a staining developer. If possible the best course of action would be to just make a new print if one has the negative.

Arklatexian · Feb 11, 2018

Ian Grant said:
There were non staining Pyrogallol developers made and sold commercially I have the formulae somewhere, and both Ilford and Kodak used Pyrogallol in MQ commercial D&P developers as an oxygen scavenger.

Kodak D177 is a Pyro-Soda dish developer with Sulphite that Kodak Ltd sold as a powder packaged developer, it has 50g Sodium Sulphite (anhyd) to 12.5g Pyrogallol. I think the idea is just enough Sulphite to prevent the stain but not enough to prevent the tanning and edge effects. I have a 1939 Kodak Ltd Professional catalogue that should list it, it's in my darkroom (at the end of my garden) I'll look and see tomorrow.

D177 was one of a series of Kodak Ltd developers not made or sold by Eastman Kodak.

Ian

I have questions about Pyro (PMK) developers, etc. What is the difference between "staining" and "tanning"? When I have used PMK, I wanted all the "staining" I could get. If "stain" and "tanning" are the same, why would you want to use a developer than did not do either or both? I have only used PMK.......Regards!

John Wiegerink · Feb 11, 2018

oldtimermetoo said:
I have questions about Pyro (PMK) developers, etc. What is the difference between "staining" and "tanning"? When I have used PMK, I wanted all the "staining" I could get. If "stain" and "tanning" are the same, why would you want to use a developer than did not do either or both? I have only used PMK.......Regards!

I think staining has more to do with "coloring" the emulsion and tanning is more or less "hardening" the emulsion surface. Just a guess and if I'm wrong I'm sure somebody will correct me. JohnW

Raghu Kuvempunagar · Feb 11, 2018

“the idea is just enough Sulphite to prevent the stain but notenough to prevent the tanning and edge effects.”

This would be fantastic to get from a non-staining Pyro developer. Is it possible or as Jerry opined, are staining and tanning deeply coupled and u can’t get one without the other?

Also is tanning relatively permanent compared to stain? Does exposure to sunlight or UV affect the relief image?

Wayne · Feb 12, 2018

From an earlier post:

The following table (Lumière and Seyewetz, 1928) shows the colour of the secondary image obtained in various developers, its relative intensity and the concentration of sulphite necessary to prevent its formation.

Developer -- colour -- relative intensity -- sulphite g/litre

Pyro -- yellow-orange -- 10 -- 11
Catechol -- black -- 10 -- 6
Hydroquinone -- yellow-brown -- 10 -- 2
Chlorhydroquinone -- yellow-brown -- 10 -- 2
Amidol -- reddish-brown -- 8 -- 2
p-Aminophenol -- brownish-black -- 3 -- 2
Metol -- brownish-black -- 2 -- 1
PPD -- Grey -- 1 -- 0
Glycin -- None."

Gerald C Koch · Feb 12, 2018

With today's films getting extra hardening is really not important.

While a negative is not going to fade in dark storage each time it is printed it fades a bit. So if you are making multiple prints then fading is a concern.

Alan Johnson · Feb 12, 2018

From 100 years ago there was such a non staining developer, BJ Pyro Soda developer. I believe this went out of fashion because the high pH needed resulted in grainy negatives.

Bob Carnie · Feb 12, 2018

michael_r said:
The minimum amount of sulfite required to prevent stain depends on the composition of the developer.

Tanning is the cross linking of gelatin due to reaction of pyro oxidation products with the gelatin. Staining appears to occur mostly due to reactions between pyro oxidation products, but may also have to do with the cross linked gelatin molecules. Although tanning and staining are separate reactions, they are related. More importantly they are both inhibited by the presence of sulfite. It may be possible to find a sulfite level that inhibits stain while allowing some degree of tanning, but this would have to be determined experimentally somehow. Also note whatever you find might only be film specific since the gelatin itself is an important variable. Increased sulfite and reduced tanning might impact the degree to which edge effects are formed.

Not sure what advantages there are with a pyro developer that doesn't stain. One disadvantage should be increased graininess, because without stain you need to develop more silver. I don't think I would worry too much about the stability of the stain. When a negative is not being printed, it is typically kept in "dark storage" anyway.

good answer Micheal. Even I could understand what you are saying.

Raghu Kuvempunagar · Feb 12, 2018

Wayne said:
From an earlier post:

The following table (Lumière and Seyewetz, 1928) shows the colour of the secondary image obtained in various developers, its relative intensity and the concentration of sulphite necessary to prevent its formation.

This is very useful information. Thanks. Was this for a specific film or generally applicable for all films?

Raghu Kuvempunagar · Feb 12, 2018

Bob Carnie said:
good answer Micheal. Even I could understand what you are saying.

+1

Ian Grant · Feb 12, 2018

Ian Grant said:
There were non staining Pyrogallol developers made and sold commercially I have the formulae somewhere, and both Ilford and Kodak used Pyrogallol in MQ commercial D&P developers as an oxygen scavenger.

Kodak D177 is a Pyro-Soda dish developer with Sulphite that Kodak Ltd sold as a powder packaged developer, it has 50g Sodium Sulphite (anhyd) to 12.5g Pyrogallol. I think the idea is just enough Sulphite to prevent the stain but not enough to prevent the tanning and edge effects. I have a 1939 Kodak Ltd Professional catalogue that should list it, it's in my darkroom (at the end of my garden) I'll look and see tomorrow.

D177 was one of a series of Kodak Ltd developers not made or sold by Eastman Kodak.

Ian

I checked the Kodak Catalogue which was 1940 not 39 but there was no mention of D177 (which is in the Wartime Kodak Formulary annd post War Kodak Chemicals and Formulae - both published by Kodak Ltd). Instead Kodak were selling D190 another powder packaged Pyro-Soda developer.

Ian

Raghu Kuvempunagar · Feb 12, 2018

Ian Grant said:
I checked the Kodak Catalogue which was 1940 not 39 but there was no mention of D177 (which is in the Wartime Kodak Formulary annd post War Kodak Chemicals and Formulae - both published by Kodak Ltd). Instead Kodak were selling D190 another powder packaged Pyro-Soda developer.

Ian

Found this on the web.

Ian Grant · Feb 12, 2018

I have the actual books

Ian

Raghu Kuvempunagar · Feb 12, 2018

Ian Grant said:
I have the actual books

Ian

I don’t doubt that.

D177 seems to be using a lot more Catechol per ml of working solution than modern staining developers. Is this how it can produce substantial tanning effect while not staining in the presence of sulfite?

Raghu Kuvempunagar · Feb 12, 2018

Raghu Kuvempunagar said:
I don’t doubt that.

D177 seems to be using a lot more Catechol per ml of working solution than modern staining developers.

Pyro not Catechol.

Ian Grant · Feb 12, 2018

Pyrogallol is referred to as Pyro not Pyrocatechin by Kodak. Just spotted you're correction

Part A is diluted 150ml to 1 litre to make Part B so it's quite dilute like modern staining developers. As it's very dilute it'll be slower working so won't be anything like as grainy as conventional Pyro developers which are energetic

Ian

Pyro without stain

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