Toning - but not your grandma's toning.... (primary/complementary color toning)

[holmburgers]

Interesting about bleaching... do you think most bleaches would leave the dye-image unharmed or would care have to be taken in selecting an appropriate bleach?

So I take it I won't find Tim Rudman's book in a library.. why spend $40 when I can ask the owners here, for FREE!

 

[Vlad Soare]

Keeping the silver helps retain the blacks and the overall contrast of the picture. If you remove the silver and only keep the dye, you'll get more vibrant colors, but you'll lose density, especially in the shadows. This may be objectionable in prints, but in your case, who knows, it could be just what you're looking for...
A simple ferricyanide bleach should work fine.
Tim Rudman shows examples of these techniques in his book. He also explains the processes and how they work. Since for the time being I'm not particularly interested in dye toning, I've read this chapter quickly and superficially, so I can't give you more details right now. But if you're interested in toners of any kind, then this book is a must-have.
Prior to the reprint, the book wasn't available new anymore, and used copies used to sell on Amazon or eBay for hundreds of dollars.

 

[Marco B]

Keeping the silver helps retain the blacks and the overall contrast of the picture. If you remove the silver and only keep the dye, you'll get more vibrant colors, but you'll lose density, especially in the shadows. This may be objectionable in prints, but in your case, who knows, it could be just what you're looking for...

My guess is that the pictures above have not been bleached, so the images consist of dyes and metallic silver. By bleaching the silver and refixing you should get even more vibrant colors.

Vlad, I agree with you that retaining part of the silver maintains shadow density.

But there is one thing that I am not sure of: usually, in the normal two bath bleach/redevelop or combined single bath bleach/redevelop, there is ALWAYS bleaching going on.

The bleaching is a fundamental step in the toning of the image, as the bleached silver is replaced by another material (e.g. Prussian blue pigment blue toning), or the bleached silver reacted with another substance to form a complex (as in sepia toning, where the bleached silver reacts to form silver sulphide Ag2S, or as in selenium toning where the selenium complexes with the silver).

Now I am not familiar with these dye toners, but don't they use bleach too?

I know there are toners like polysulphides that directly react with silver without a bleach (selenium toner is one as well), but most toners seem bleach based.

Ah... now saw on Moersh's website, that the Multitoner does contain a bleach:

"100ml Bleicher" is mentioned, which is bleach. So this dye toner will bleach the silver, and the amount of dye toning should be determined by the amount of bleaching than...

 

[Vlad Soare]

Well, as I said, I've read this particular chapter only superficially and can't remember all the details. I'll read it more carefully tonight, when I get home.
I can't remember why Tim Rudman mentioned bleaching the silver after toning to get vibrant colors, instead of simply bleaching the image completely prior to toning. I'm not very familiar with the way dyes and dye couplers work, but I think the dye might need some silver to cling to.
I'll have to read this chapter again.

 

[Marco B]

I can't remember why Tim Rudman mentioned bleaching the silver after toning to get vibrant colors, instead of simply bleaching the image completely prior to toning. I'm not very familiar with the way dyes and dye couplers work, but I think the dye might need some silver to cling to.
I'll have to read this chapter again.

Vlad, I have no doubt removing all silver by bleaching after toning eads to a more vibrantly colored image as Tim mentioned, since you are removing the black of the images silver obscuring the dye tone.

However, you are right , that bleaching the entire image before toning (or toning to completion in a single bath bleach/redevelop toner), will lead to an even better and more vibrant result.

If you bleach away the silver AFTER toning, part of the silver will not have formed dye, and thus, you will not have the maximum possible dye content on the print, and consequently not the maximum vibrancy / saturation.

In fact, bleaching after toning can result in an unwanted loss of shadow detail and contrast...

 

[Marco B]

Of course, if one desires a lower contrast image, there is nothing wrong with bleaching the image after a partial toning, as a creative method, but some of the image detail is likely to suffer.

 

[Vlad Soare]

OK, I got home and read it again. It's all clear now.
Dyes don't work like regular indirect toners. They don't simply replace silver halides, like indirect sepia toners (for instance) do.
The black and white image is first bleached completely, then redeveloped in a color developer, which produces a silver image along with some development by-products. These by-products activate the dye couplers in direct proportion to the amount of metallic silver formed.
So the final image is composed of silver and dyes.
Subsequently the silver can be bleached again, followed by fixing, to leave just the dyes alone.

 

[Marco B]

OK, I got home and read it again. It's all clear now.
Dyes don't work like regular indirect toners. They don't simply replace silver halides, like indirect sepia toners (for instance) do.
The black and white image is first bleached completely, then redeveloped in a color developer, which produces a silver image along with some development by-products. These by-products activate the dye couplers in direct proportion to the amount of metallic silver formed.
So the final image is composed of silver and dyes.
Subsequently the silver can be bleached again, followed by fixing, to leave just the dyes alone.

Interesting, thanks Vlad! I have never used dye based toners, so this info is new to me. Good to learn something new. Still need to get Tim's book... it's on a growing list of "things-to-buy"

 

[holmburgers]

Something I've struggled to understand for a while is this; do dye-couplers have to be present in the emulsion? I think the answer is no, but I'd love to have some clarification on this.

 

[Vlad Soare]

It depends. If you're talking about chromogenic toners meant for black and white prints, then no, they don't (otherwise they could not work, since obviously black and white papers have no dye couplers in the emulsion). The dyes are added during color redevelopment. A chromogenic toner kit consists of a bleach, a color developer, and three dye couplers - yellow, magenta and cyan. You mix the developer with one or more dyes, in the proportions required to make your desired color.
If you're thinking about color films and papers, that's a different story. Though the dye couplers don't actually have to be embedded in the emulsion, they are embedded for cost and convenience reasons. Adding the dye couplers during processing would not be impossible (after all, that's how Kodachromes worked), but the whole process is much simpler and more reliable if they are already there.

 

[holmburgers]

Ahh, thanks for the clarification. I was a little mistaken then, in my understanding of C41 & E6 films.

By the way, Kodachromes do work like that!

 

[Vlad Soare]

Indeed, it's a bit early to use the past tense. They still do work until the end of the year.
Developing Kodachromes requires an expensive and complicated machine, which must be perfectly calibrated and must be operated by a qualified person, who must have a deep understanding of the whole process. By contrast, an E6/C41 machine is cheap and can be operated even by a monkey. That's why having dyes in the emulsion is cheaper and more convenient.

 

[Photo Engineer]

Vlad;

I have witnessed the processing of Kodachrome by hand many times. It is possible with the right chemical solutions and the right process sequence! After all, that is the way the R&D process brought Kodachrome to fruition.

Couplers + p-Phenylene Diamine developers = Dyes + Silver. WIthout a bleach, the dyes are quite muted and contrast is high. Sometimes, if 4 equivalent couplers are used, leuco dyes form which are colorless and cannot form the final dye unless oxidized in a separate oxidant bath.

This method though, of using couplers and a PPD developer, will give you 3 full color images which can be superimposed to yield a Kodachrome like transparency. This was common as were the other processes using toners and pigments in the 40s as methods to get full color transparencies or prints.

PE

 

[Vlad Soare]

I have witnessed the processing of Kodachrome by hand many times. It is possible with the right chemical solutions and the right process sequence!

Ron, I'm sure it's possible, I see no reason why it shouldn't be, but it's not easy. It's much more complicated than E6/C41, and there are more things that can go wrong, more things to worry about.
In fact, I can't imagine myself doing K-14 at home, even if I had access to all chemicals.
But then, all I know about Kodachrome and K-14 was read on the internet or in books. Maybe I'm wrong. Maybe if I had the chance to see the process with my own eyes I would think differently.

 

[Photo Engineer]

K14 is like running 1 E6 process and 2 C41 processes in a row with a selective reexposure between two of the color development steps. It is not hard, it is time consuming. Actually, dye transfer is longer and harder and much more complex. Done that too!

PE

 

[holmburgers]

Is the selective re-exposure 'selective' in the fact that it is a colored light source? Sounds fascinating, and reminds me of some of the tri-pack* development methods in Friedman's book (*if I'm not mistaken).

 

[Photo Engineer]

The red exposure is from the back and the blue exposure is from the front of the film.

IE: Red exp, cyan develop, wash, blue exp, yellow develop, wash fogging magenta develop, wash, bleach, fix, wash etc. This assumes a first developer has formed the negative silver image. This can be done using a separation camera with no selective reexpsure.

PE

 

[holmburgers]

Ahhh, I see. These are the "tricks" (or maybe a better word would be "innovations") that make monopacks possible I guess.

So let me see if I've got this right. The red exposure doesn't affect the blue layer, because it's not panchro, and therefore the cyan developer has nothing to develop in the blue layer. And the blue exposure doesn't have any affect on the red layer because it's developed by that point. Same goes for the yellow developer. The foggant (thiourea?) exposes the green layer and the magenta developer can only affect that layer by this point.

I'm slightly confused as to how the magenta layer remains unaffacted through these steps though. What am I forgetting/missing?

 

[nworth]

My guess is that the pictures above have not been bleached, so the images consist of dyes and metallic silver. By bleaching the silver and refixing you should get even more vibrant colors.

I don't know if you're aware of this, but Tim Rudman's book has been reprinted and is available from Silverprint for just 25 pounds. Their minimum amount of 100 pounds for international orders does not apply in this case; it's possible to order just the book alone.

There are a couple of approaches to dye toners. The ones that give the most intense tone to the image use a special bleach which forms a mordant for the dye from the silver image. You can control the toning to some extent by controlling the amount of bleaching.

 

[holmburgers]

Any idea what kind of bleach does this?

I'm learning a lot, thanks everyone!

 

[nworth]

Most that I have seen are ferricyanide based. Silver ferricyanide is a good mordant. An example would be:

Potassium ferricyanide 5 g
Ammonium dichromate 1.5 g
Sulfuric acid 3 g
Water to make 1 l

But copper and potassium triiodide have also been used:

Copper sulfate 40 g
Tribasic potassium citrate 60 g
Acetic acid (glacial) 30 ml
Potassium ammonium thiocyanate 20 g
Water to make 1 l

and:

Iodine 15 g
Poyassium iodide 50 g
Acetic acid (glacial) 25 ml
Distilled WTM 1 l

 

[Marco B]

There are a couple of approaches to dye toners. The ones that give the most intense tone to the image use a special bleach which forms a mordant for the dye from the silver image. You can control the toning to some extent by controlling the amount of bleaching.

For anyone wondering what a "mordant" is, like I did, here is the Wikipedia description:

http://en.wikipedia.org/wiki/Mordant

And another maybe even better description:

http://stainsfile.info/StainsFile/theory/mordant.htm

Beware, both articles assume some chemistry knowledge...

Holmburgers, be aware that if the bleach is used as a mordant before toning, and NOT to simply remove the silver image after toning in combination with a fixing step (in which case it ISN'T used as mordant, but simply as a bleach), than the mordant choice can have a pronounced effect on the color of the resultant image, as the metal ion forms a complex with the dye molecule (called a "lake"), often resulting in a significant color change, see the links above.

Marco

 

[Photo Engineer]

The Potassium Triiodide would be my last choice!

The Iron mordant can form blue stains.

See Friedman.

PE

 

[holmburgers]

Check out eBay item #260664917755

Unfortunately it only has an hour left so who knows how long it'll be visible.

But it's a 2-color separation w/ one transparency toned blue and the other red. The photos show them separately and then registered.

Any likely ideas as to how this toning was achieved? This is what I want to do, but with 3-color. Also, why would this have been created... what for, by whom? Was it a commercial process?

Thanks!