Post staining a negative.

[waynecrider]

In an old article I read on the advantages of using Pyro for PT printing, Bob Herbst notes that highly oxidized Pyro can be used post processing to increase the overall stain density of a negative to salvage a thin negative or to increase the contrast slightly in the lower values. A dried negative can be re-wetted to produce the same effect. Not being one to use Pyro, I am wondering if it is possible to produce some effect on a film developed in a non-Pyro developer for PT/PD printing; Essentially if it is possible to produce any stain or get any effect.

 

[JBrunner]

In my experience with PMK on PMK, it only would seem to increase the overall stain, because there is no developer action, and I suspect that might be the case in this scenario, but If you try it, then we will all know.

My current tendency would lean toward a selenium bath to reliably thicken up a neg.

 

[gainer]

The best way to do what you want is to use a rehalogenating bleach such as is used with sulfide toning of prints and then redevelop the bleached negative in the staining developer of your choice. PMK is a good choice. Just be sure the bleach is the rehalogenating type, not Farmer's reducer. You can make your own with potassium ferricyanide and potassium bromide. A recipe is in the Darkroom Cookbook as solution A for Ansco 221 Sepia Toner. Bleach to completion. Redevelop to completion. If you're using PMK, the second solution need not be Kodalk. The grain and gradations are not influenced by the B solution the second time around, so you could use a carbonate solution. Also, neither the amount of A solution nor the ratio of A to B are critical. The silver image will be restored and the stain image added if there was none or intensified if there was. Be sure that the original negative was properly fixed and washed before you do this process.

The process can be repeated, but be aware that the negative is tanned as well as stained and the emulsion may crack from the strain.

This process does not add overall stain if there is no silver fog already present. It might be possible to ... I'd better not go into that. I'm only telling you what I have tried and reported in Photo Techniques mag in an article "More Pyrotechincs"

 

[waynecrider]

Well if that's the case I may as well get some Pyro and just use it for developing and keep the oxidized leftovers. The last stuff I used, Pyrocat, didn't last very long in the bottle although I flooded the bottle with nitrogen, so I went back to other standard developers, currently Xtol.

 

[gainer]

Pyrocat MC in glycol will last a long time. So will Pyrocat HD and Pyrocat PC.

I don't grasp why you would want to keep the oxidized leftovers of Pyro. I presume you mean Pyrogallol. If you want the high contrast for platinum or other and don't care if you can print on ordinary paper, you can develop the heck out of it with Dektol or something right from he start.

If you want to intensify the contrast of any BW negative, you can use the bleach-redevelop process with PMK or any of the Pyrocat developers to do it. An advantage to any of the staining developers is that the stain image gives high contrast for blue or UV sensitive papers and lower contrast for VC papers, so you can use the same negative on both. Bathing in oxidized developer does not do that.

 

[waynecrider]

The Pyrocat I tried expired pretty quick. About 2-3 months, and is not the types you have mentioned which are newer.

I wouldn't keep oxidized leftovers if I was using for example Herbst's pyro-metol formula; But I'm not using Pyro in any form. If I was, or started again, I would not be asking questions. This only concerned negatives say developed in Diafine for example. Thanks for the info on the bleach re-develop process.

 

[gainer]

BRD certainly works for negatives originally developed in non-staining developers such as Diafine. The bleaching solution is reusable and lasts quite a long time, so is handy to have around. The Pyrocat series in glycol is available from Photographers Formulary . I'm partial to Pyrocat MC for some reason.

 

[bobherbst]

Post Staining

Immersing an already developed negative in oxidized pyro will only add an overall stain of equal density to the entire negative which is essentially the same as adding fog to the negative and extending printing times for alternative processes with no improvement in contrast range. The stain will not be proportional to the silver density. If you use any pyrogallol formula to develop your negatives, NEVER use a post stain step if you are printing alternative processes. Printing times will be excessively long. I covered this subject extesively in an appendix of Dick Arentz's second edition of Platinum & Palladium Printing book and in articles in View Camera magazine. Stain can be your friend but it can also be your enemy in alternative processes if over-used.

Bob Herbst

 

[jim appleyard]

Wayne, if you don't want to use pyro, I wonder if you could sepia tone the negs? With or without the bleach? This may be along the lines of Pat Gainer's thinking, but without a developer. IIRC, Tim Rudman goes into sepia toning with negs, but I don't have the book here. Just thinking outloud...

 

[gainer]

Sepia toning will require a bleaching step. The image restored by the sulfide solution will be a different color, and I don't believe it will be any higher contrast for printing, but if so it won't be much. The same bleached negative, redeveloped in a Pyro solution, will have its silver image restored with the proportional dye image added.

For many purposes, redeveloping in a solution of hydroquinone + carbonate will produce a usable stain color, and it will be added proportionally, not as an overall stain, just as with pyrogallol or catechol. The proportions of hydroquinone to carbonate are not critical, as redevelopment will be to completion. It cannot be overdone because it will stop when all the silver is restored. The redeveloped negative will have increased contrast for graded papers. Multigrade filters will not have exactly the same effect as before on VC papers, but will have a degree of effect that you can find by trial and error. That's why the Creator invented test strips.

 

[gainer]

Immersing an already developed negative in oxidized pyro will only add an overall stain of equal density to the entire negative which is essentially the same as adding fog to the negative and extending printing times for alternative processes with no improvement in contrast range. The stain will not be proportional to the silver density. If you use any pyrogallol formula to develop your negatives, NEVER use a post stain step if you are printing alternative processes. Printing times will be excessively long. I covered this subject extesively in an appendix of Dick Arentz's second edition of Platinum & Palladium Printing book and in articles in View Camera magazine. Stain can be your friend but it can also be your enemy in alternative processes if over-used.

Bob Herbst

The kind of post staining you refer to is what veteran pyro users sometimes have on their hands and on their utensils. It is not the only kind of post staining. The bleach and redevelopment method produces a proportionally stained negative that is just like a negative developed in PMK or Pyrocat XX to the same silver contrast. That negative could then be completely bleached in Farmer's and would still have the stain image which could be printed on very high contrast material.

 

[waynecrider]

Thanks for chiming in Bob. The article that I quoted is "The Advantages of Using Pyro for Platinum Printing", View Camera Sept/Oct 1997. Great article and pictures btw.

 

[cahayapemburu]

Dr. Tim Rudman recommends sepia toning negatives for increased contrast of up to 2 1/2 paper grades.

 

[gainer]

Nevertheless, it is no less difficult to redevelop in a sulfide solution than in a hydroquinone-carbonate solution, and you gain a negative that has high contrast for graded paper and variable contrast for VC paper.

 

[cahayapemburu]

Have you tested to find the differences in the contrast increases gained by each method? Either way, one ends up with a stained negative that increases print contrast with either graded or VC papers, but the speia toned negative also benefits from added archival properties, just as a sepia toned print would.

 

[gainer]

The sepia negative is not stained silver. The silver is replaced by silver sulfide. If silver sulfide is optically more dense than silver, you will get increased contrast. In redeveloping by pyro or other staining developer, the silver image is restored and the proportional stain is added to it.

There are pyro-developed negatives that have been around a long time. I have not heard anyone say that a pyro-developed negative is any less archival than any other.

 

[gainer]

Anyway, when you are through redeveloping in pyro, you still have the silver image available for sepia tonong if you think it will help.