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It's not about the materials being exactly alike, that doesn't matter. What does matter is recognizing that Capstaff's procedure is always a 2-color process, but a 2-color process is not always the Capstaff procedure... that's all I guess.
At any rate, I think what you're talking about is interesting and by all means you should carry on! 
The hologram films/plates do offer a unique advantage, admittedly, being the only emulsions that are both transparent and sensitized to only red or green. This can make an easy bipack; just pop a yellow filter on and voila. That is brilliant. I guess I wasn't thinking about how to get the separations as much as what to do with them once we had them.
This probably isn't practicable, but how about this for a bipack?... 3 different elements, sandwiched together behind the lens in this order; a film coated with liquid light, a very thin yellow acetate sheet, and a sheet of ortho film. You'd get a blue record and a green record. Or substitute the yellow acetate for red, and the ortho for panchro; you get blue and red records.
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for portraits I think three sheets would work just fine---particularly if you exploit some lenses with chromatic abberation--yo know...the blue focuses before the red--so maybe a portrait camera using a regular mensicus but that meniscus would have the chromatic abberation corrected by the film placement...and then you get a regular spherical abberation portrait lens---can actually do all 3 colors that way in the tripack.
but up close with longer lenses...with people portraits, I don't think that the focus erors from film thicknesses will be a problem--hell--the 11x14's I shoot I know must sag considerably..and it don't ruin portraits.
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I've only recently come across this thread and was interested in the discussion of the so-called "pinatype" dyes. Unfortunately, the 1911 article which discusses the dyes does not use modern nomenclature, so other than dyes with classic names such as eosin, it is very difficult to determine which dyes were tested. Capstaff in his original patent, US 1196080, describes the dyes as "acid (preferably the salt of a sulfonic acid)". As near as I can tell the dyes in the Kodak dye transfer method, Acid blue 45, Acid red 80, and Acid Yellow 11, all have a sulfate group and are acid dyes. Therefore they might fit the requirements of Capstaff's patent. It is logical that dyes suitable for relief matrices would also work with planographic matrices.
The Capstaff patent, however, mentions one critical step necessary for a planographic matrix: the gelatin must be dried out before being immersed in the dye bath. As a side-note, the original processing for the Godowsky and Mannes dye-coupler Kodachrome required that the film be dried out thoroughly before being immersed in the bleach bath. This allowed the controlled diffusion of the bleach into just the outer, (yellow), or outer two, (yellow and magenta) layers. Godowsky and Mannes might have been familiar with the Capstaff process before inventing their controlled diffusion bleach system.
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Pinatype dyes
I've only recently come across this thread and was interested in the discussion of the so-called "pinatype" dyes. Unfortunately, the 1911 article which discusses the dyes does not use modern nomenclature, so other than dyes with classic names such as eosin, it is very difficult to determine which dyes were tested. Capstaff in his original patent, US 1196080, describes the dyes as "acid (preferably the salt of a sulfonic acid)". As near as I can tell the dyes in the Kodak dye transfer method, Acid blue 45, Acid red 80, and Acid Yellow 11, all have a sulfate group and are acid dyes. Therefore they might fit the requirements of Capstaff's patent. It is logical that dyes suitable for relief matrices would also work with planographic matrices.
The Capstaff patent, however, mentions one critical step necessary for a planographic matrix: the gelatin must be dried out before being immersed in the dye bath. As a side-note, the original processing for the Godowsky and Mannes dye-coupler Kodachrome required that the film be dried out thoroughly before being immersed in the bleach bath. This allowed the controlled diffusion of the bleach into just the outer, (yellow), or outer two, (yellow and magenta) layers. Godowsky and Mannes might have been familiar with the Capstaff process before inventing their controlled diffusion bleach system.
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More on Pinatype dyes
Apologies for double-posting the previous text. Friedman in "History of Color Photography" in the first two pages of Chapter 26 gives a good discussion of pinatype dyes; he even addresses the 1911 article from Brit. J. Phot. vol. 58. He mentions specifically the natural dye carmine, among other types, and he gives a broad discussion of the chemistry of suitable dyes.
In particular "sulphonic groups", (which I take for "SO3" groups), caused the dye to stay in the gelatin; while "nitro groups" (NO2) caused the dye to wash out easily. It seems likely that many azo dyes with a SO3 group could be good candidates for pinatype dyes.
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You may have missed this but the terminology is connected to the Pina Cryptol family of dyes. It has been found that more than one SO3- group is useful in making the dye fast in gelatin and even mordants are used.
The archetype dyes of this nature today are the Solantine class (Solantine Pink and Solantine Yellow) and then there is my old favorite Chicago Blue. A mix of the pink and yellow will probably satisfy the Capstaf short wavelength dye, and Chicago Blue itself will supply the long wavelength dye.
The PINA designation is no longer used.
PE
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Acid dyes
I assume that these are the same dyes that you recommend for the dye bleach color emulsion described on page 171 of your book, "Photographic Emulsion Making, Coating and Testing".
Looking at internet images of the structures, Solantine Yellow (C.I. 13950) appears to be an azo dye with two SO3 groups; Solantine Pink (C.I. 25380) appears to be a diazo with four SO3 groups and two aniline groups. The dye called Chicago Blue appears to refer to two structures, Chicago Blue 4b and Chicago Sky Blue. From what I can tell it also has azo groups with four SO3 groups. I can't find a C.I. number for Chicago Blue. All this is consistent with acid dyes which can be reduced and made colorless in the dye bleach process outlined.
Their diffusion properties are interesting. Do they stain untanned gelatin and not tanned gelatin? Has anyone tried staining a dry gelatin tanned matrix? Could the diffusion rate be regulated by Ph?
It is surprising to see the great interest people have shown in Capstaff's two color photography. Incidentally, I am looking forward to getting volume two of "Photographic Emulsion Making" and learn more about color emulsions. I hope you're not being threatened with being chained in the barn until you finish writing it.
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These dyes would probably work well for both Dye Bleach and Dye Transfer. However, Solantine Pink is a bit short as is Chicago Blue, but I have made good DB coatings with all 3 and reasonably good images. That is why I think that if they transfer, they would work well with a 2 color process. You need an orange and a blue approximation.
They are similar to DT dyes, and should transfer once the emulsion is tanned. I'm not sure though.
I am still looking at options. The barn and chains or another book. With one, I would hop I get fed, I know I have a "room". With the other I have to pay for my own keep. Decisions, decisions!
PE
PE
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Well, I'm certainly looking forward to another book. In the Technicolor DT process the dye solutions were loaded with acetic acid, but the Capstaff patents don't mention this. Neither does Capstaff mention temperature, although this was critical in Technicolor DT.
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I suggest experimentation.
PE
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