Capstaff's two-colour Kodachrome process.

Hello there everyone. As I spend my time on this part of the APUG forums, I generally spot quite a bit of interest in the now sadly discontinued Kodachrome film product together with the ghastly difficult K-14 process. I'm sure that most people recognise Kodachrome as the slide film made by Kodak invented in the mid thirties.

However, it might be interesting to note that the years leading up to the First World War, the word "Kodachrome" was in fact used to denote another product that used a 2 colour process. Simply states, you took two different negatives through filters (red and green) which after regular processing were bleached and dyed, one in a kind of bluish green (I want to say teal?) and the other in a kind of burnt orange colour. Afterwards, when you took these two positive transparencies together in registration on a light table, it made the appearance of a full colour photograph.

Now, one important thing to note is that since this is a two colour process involving essentially red and green, it fails to accurately reproduce blue, violet, magenta, and purple. However, it would serve to be useful for colour portaiture because of its ability to reproduce flesh tints, red, orange, green, gray, and black. The photographs themselves are surprisingly sharp and the colours themselves are accurate, rich and very true to life (at least for the spectrum they reproduce). Now, I have with the help of user "holmburgers" been able to find literature that addresses this process together with patents that might help someone get started if he or she would want to investigate further. I will provide the linkThis post over at New55 has all the pertinent links and gives some idea of the method. below.

One thing that is a bit frustrating is that it does not seem that the formulas for the dues that are used for the process have ever been publicised. One must give me pardon for my lack of knowledge in photographic chemistry, but I do not know how one would go about creating such dyes from scratch. I hoped that perhaps with help from others more knowledgeable than me, some light might be shed on that particular subject.

As I see it, this process does not seem particularly difficult to do granted one has access to the required materials. It does not seem to produce any more of a challenge than, say, toning a print or something in that manner. Some people might disagree, but I find that the Capstaff process might be interesting to pursue further, as it offers interesting results for anyone that successfully manages to reproduce it accurately.

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Links for further literature:

http://new55project.blogspot.com/2012/03/early-color-transparencies-at-george.html

-->The given post over at the New55 website has all the relevant links and gives some idea of the method together with some relevant information in the comment section, such as links to patents produced by Mr. Capstaff.

I did some work with T-Max 100 developed as a positive, one exposure with a red filter and another with green.
I then tried some dye mortanting recipes from Wall's book . Finding the right dyes and its concentration are the problem. I tried Rhodamine6G
and Malachite green I got some kind of results,but nothing close to reality.

This was going to be my plan B when they stop making color film
rob

In a nutshell, Capstaff's Kodachrome worked by taking a silver-gelatin negative and exposing it to a tanning bleach, not unlike a carbro bleach or a dichromate bleach. This bleach reacts with the silver and hardens the gelatin in proximity, "tanning" the highlights (a.k.a. making the gelatin much harder and less soluble; cross-linking). Areas with less silver aren't tanned as much, i.e. the shadows.

This kind of image is known as a planographic matrix; an image in gelatin defined by differences in degree of tanning. This is what you create in bromoil, by the way.

Next step, dip these in the dye baths and voila; dye absorbs more freely into the untanned gelatin & less freely into the highly tanned areas.

What R Paul is describing is in fact a different process that relies on turning the silver into something like potassium iodide(?), which is a dye mordant and then dying the films with basic dyes (F.E. Ives pioneered this I believe, for his Kromskop process). Although dichromates are something of a mordant, they're washed out in 2-color Kodachrome and thus the staining mechanism is actually an interaction between dye & gelatin.

Capstaff's process requires acid dyes; which is actually a good thing. Basic dyes are incredibly vivid but relatively fugitive in terms of light stability. Acid dyes are generally less saturated but have very good long term stability; one reason why dye-transfer prints have such excellent dark keeping. The two dyes react with gelatin totally differently, another reason why we need acid dyes for this process. Acid dyes are also used in textile dying, meaning a great variety are commercially available.

Now, the tale of these dyes is quite interesting. It all goes back to an early dye-imbibition process called Pinatype which used planographic matrices exposed under positives to create matrices capable of absorbing and transfering dye to a final support. We can call these dyes "Pinatype dyes", and what (supposedly) makes them unique is that they preferentially stain untanned gelatin over tanned gelatin. J.S. Friedman wrote quite a bit about these dyes; indicating that knowing their names or class would be beneficial to everyone. In one journal there is actually quite an impassioned discourse on this topic (which I can find if anyone is interested).

So, historically these dyes are considered "secret", or at least were so in the late 40's.

But, all hope might not be lost. It's reasonable to assume that many dyes, in fact maybe all acid dyes (or reactive dyes, or direct dyes) have this property. A good place to begin is looking at (there was a url link here which no longer exists).

I should also note that there are some other ways to go about making the gelatin "matrix". One would be to use dichromated gelatin exposed to UV under a positive (not a negative; it makes sense if you think about it and the result is the same as a negative exposed to a tanning bleach). This would also create a planographic matrix. Lastly, and perhaps the easiest, would be to expose dichromated-gelatin under a negative and etch it with hot water (like in the carbon process), creating a relief matrix. A relief matrix is exactly what a dye-transfer matrix is, and the whole thing would consist of equally tanned gelatin that would dye up in proportion to its thickness (as opposed to its degree of tanning).

So in other words, we can completely eliminate this concern of "Pinatype dyes" (if such a thing really exists) and start working with relief matrices, of which an innumerable quantity of dyes will work with. Or we can investigate if it's possible to get these same dyes to act in a Pinatype or Capstaff fashion with planographic matrices.

I hope this is helpful, if not somewhat overwhelming. These Capstaff Kodachromes are really beautiful and worth pursuing, and I plan to start working on them in the fall.

In one journal there is actually quite an impassioned discourse on this topic (which I can find if anyone is interested).

Click to expand...

I am interested in references and original documents if they are possible.

Umut

Sure thing Umut,

Here are two excerpts from American Photo, Volume 34 (circa 1947 I believe). I can email anyone the complete series from this volume (inquire through PM please), but I'm only including the two relevant pages here. The second attachment, page 362, includes Friedman's plea for discovering suitable pinatype dyes.

Also, just noticed this reference,

"L. Lemaire (British Journal of Photography, Vol. 58 (1911), p. 969) made a study of the chemistry of the dyes which were suitable for the pinatype process."

Need to find this one too...

Thank you Chris ,

Can you please send the document to my gmail account with bc and cc filled with same address otherwise its lost. I will pm you also.

Umut

holmburgers said:

Lastly, and perhaps the easiest, would be to expose dichromated-gelatin under a negative and etch it with hot water (like in the carbon process), creating a relief matrix. A relief matrix is exactly what a dye-transfer matrix is, and the whole thing would consist of equally tanned gelatin that would dye up in proportion to its thickness (as opposed to its degree of tanning).

So in other words, we can completely eliminate this concern of "Pinatype dyes" (if such a thing really exists) and start working with relief matrices, of which an innumerable quantity of dyes will work with. Or we can investigate if it's possible to get these same dyes to act in a Pinatype or Capstaff fashion with planographic matrices.

Click to expand...

As we say in Norway, I think I just had an aha-moment. I did not think of turning the process around like that. Just wonderful.

So, one essentially creates a pigment-less carbon transfer glop solution to be poured on to a tissue, then sensitized, exposed and etched? What would the support tissue be made out of? Something clear like polyester? Or am I making incorrect conclusions here?

holmburgers said:

Also, just noticed this reference,

"L. Lemaire (British Journal of Photography, Vol. 58 (1911), p. 969) made a study of the chemistry of the dyes which were suitable for the pinatype process."

Need to find this one too...

Click to expand...

If you can't find it, I should be able to get a copy from the George Eastman House Museum Library.

Land Effect from Scientific American 1959

I though you might be interested in this experiment. See http://www.aw3rd.us/scief/colorviz.htm

Prof_Pixel said:

Land Effect from Scientific American 1959

I though you might be interested in this experiment. See http://www.aw3rd.us/scief/colorviz.htm

Click to expand...

That looks like what I got when I tried it out. No true colors ,but shades of red-orange instead

Swellastic said:

As we say in Norway, I think I just had an aha-moment. I did not think of turning the process around like that. Just wonderful.

So, one essentially creates a pigment-less carbon transfer glop solution to be poured on to a tissue, then sensitized, exposed and etched? What would the support tissue be made out of? Something clear like polyester? Or am I making incorrect conclusions here?

Click to expand...

You're absolutely correct!

The best support is this (Photographer Formulary's Subbed Melinex, a.k.a. polyester). Fixed out lith film, or LF film would also work well. Alternatively, you could do a carbon-like transfer to any surface, even glass.

I'm experimenting with pigmentless glop for dye-imbibition, and one thing that's improtant to add is an "extinction dye", in most cases tartrazine or FD&C Yellow 5 food coloring. This limits UV penetration, giving a nice thin relief image and subsequently washes out during the etch.

Thanks for posting the Land effect, that's fascinating. The strength of this 2-color approach is that some subjects look really good. Particularly flesh tones, which as you can imagine was probably the most important thing to render pleasantly. Also, wood, metal objects, hair, plants, etc.; basically anything you'd encounter indoors.

I can't help but think that these two color photographs are reminiscent of very warm tungsten lighting, or better yet fire light. And wouldn't it make sense that Capstaff and Eastman, indeed that whole generation of people, would be well accustomed to life without electric light? (certainly in their youth)

To talk a bit about the color theory behind it; the Capstaff process takes two exposure behind a red and a green filter and makes the separations teal and red-orange respectively. I'm curious how wide- or narrow-band these filters should be, but I assume that red 25 and green 58 would be a great place to start. Presumably the separation filters are narrow and the reproduction colors are rather wide in their spectral absorption, that is, they overlap into their adjacent secondaries to produce a more balanced (though inaccurate) palette. There are also a number of Wratten filters designated for "two color photography", and although some are likely intended for projection, some might be intended for making the separations.

* in case somebody missed this in the link above... http://image.eastmanhouse.org/files/GEH_1987_30_01.pdf

Dye-Toning of Lantern-Slides and Other Transparencies on Glass, by Louis Lemaire

Found it!

British Journal of Photography, Vol. 58 (1911), p. 969-971 - link here

You can open it as a PDF and print out just the pages you need, or you can "read online", or any number of options off to the left of the page. I've also attached it in 3 JPGs.

Haven't even had a chance to read it yet, but isn't the internet amazing? Archive.org rarely disappoints!

It appears that the Traube Diacrhome process that's referenced in this article is similar (if not identical) to the dye mordant process that R Paul alluded to and that F.E. Ives utilized.

This article gives a very clear idea of the necessary type of dyes and notes 3 possible characteristics. One is that the dye simply doesn't color gelatin period, the second that it stains only the shadows/unexposed portions and leaves the highlights clear, which is what we'd need if we were working with planographic (or Pinatype) matrices, and the third is that the dye stains the whole matrix equally. This last characteristic is probably what we see with most imbibition dyes and this kind of dye would only work in a relief matrix (hot water etched) type of system.

Oh wow. So not only does one get to make colour slides, but there is also the advantage of getting some free training for some possible future carbon printing (at least in terms of making the glop). Is it necessary to follow some particular formulas, or can only simply make glop as one would for carbon printing? I guess if the latter is the case, then one would simply need to figure out how much extinction dye is neccesary to add in order to get a proper matrix.

One thing I wonder is what kind of dyes imbibe with the matrices? Pardon if my questions seem foolish. I'm getting very, very excited about this, but I lack some knowledge which I guess comes with experience. I haven't been able to do much alternative process, to be honest. Chemicals are frustratingly difficult to get a hand of in Norway - particularily "dangerous" chemicals like bichromate of potash

One last thing (oh God, I hope I'm not asking too many) I remember once seeing a video on colour carbon printing by one Mr. Tod Gangler where he used some kind of rod to cover pigmented emulsion on a support sheet. It looked like one of those wired coating rods used by laboratory technicians. I would imagine that such an item would make the coating easier. What rod size would one need to get a proper cover on the support sheet?

holmburgers said:

Also, just noticed this reference,

"L. Lemaire (British Journal of Photography, Vol. 58 (1911), p. 969) made a study of the chemistry of the dyes which were suitable for the pinatype process."

Need to find this one too...

Click to expand...

You can find the entire BJP vol 58 at Dead Link Removed

It's over 100mb


Edit: I see holmburgers also tracked it down while I was looking and downloading it.

Here's a good starting point for a gelatin "glop".

8% gelatin, 5% yellow food coloring (I've been using McCormick's), 1% sorbitol (you can just use sugar).

A Mayer rod (meyer rod, wire wound rod, metering rod, etc.) is great but by no means necessary. Take your film base, tape it around the edges with masking tape to a leveled piece of glass, pour on about 0.5mL/in² and spread around with your finger or, what I've found to work really well, a comb.

I'm sure you can find some potassium or ammonium dichromate somewhere, but if you can't you could look into using (there was a url link here which no longer exists) (but that's a whole 'nother project in itself!)

As for "what dyes imbibe", well that's a tough answer to give succinctly, and I'm not even really sure if I know the answer. There are a couple ((there was a url link here which no longer exists), (there was a url link here which no longer exists)) dye-imbibition threads that I've created in the past. There's a huge list of dyes (above) and then there are the ones mentioned in this most recent BJoP article.

But it's true that any dye related to dye-imbibition (dye transfer) is going to be cyan, magenta or yellow, and suited for relief matrices and not planographic matrices (though we can't be sure until we test).

Textile dyes are probably the best place to look from a hobbyist perspective. Check these out... http://www.jacquardproducts.com/acid-dye.html

Remember that acid dyes, shown in the reference above, have an affinity for proteins which is what gelatin is. Therefore, acid dyes may not wash out properly once imbibed.

PE

Prof_Pixel said:

You can find the entire BJP vol 58 at Dead Link Removed

It's over 100mb


Edit: I see holmburgers also tracked it down while I was looking and downloading it.

Click to expand...

Interestingly page 16 mentions Verichrome a B&W film introduced a few yeras earlier by Wratten & Wainwright in the UK.

This early Kodachrome came from the same research as both Mees & Capstaff had mover to set up the new Rochester Research facility after George Eastman bought Wratten & Wainwright, (he had already tried to buy Ilford twice). Other members of the company remained in the UK to found Kodak's Harrow Research facility.

Sometimes the true International nature of Kodak at it's height is forgotten. There were products sold in the UK & Europe never made or marketed in the US, and Kodak Ltd (UK) had close links to many UK manufacturers of equipment and even acted as distributors in Australia, New Zealand etc (Ross lenses for example).

Ian

At our GEH lunch yesterday, this topic came up and Mark mentioned that Capstaff had used 2 dye sets. The early set was not as good as the second set. Then he showed us lantern slides made from an ortho and a pan sensitive film that was made by Mees. We discussed the shipping methods used by W&W to deliver film world wide. It was tinned like canned fish!

We also viewed the 25th anniversary, 50th anniversary and 75th anniversary celebration plans for KRL. A bit OT, but Capstaff was in there. I also saw an excellent picture of Ross behind the camera filming for the 25th anniv. celebration.

PE

Hollywood also had its early flirtation with two-color photography, and there's probably more in print
per that kind of application than still photo.

I saw many grade "B" Hollywood productions using the 2 color method. They were awful movies and awful color.

PE

Thanks guys,

Ron, I can't wait to pick Mark's brain on this topic; had no idea there were 2 dye sets!

Well, I guess you could say something fishy was going on...

THIS is what I'd like to at least get working myself--I'm particularly interested in two color that can be merged (mirror images)--I'd LIKE to register 2 pieces of regular film (reversal processed) in glass to make a 2 color transparency.

now what would be the quickest way to do this, you experienced people? Say I shoot 2 sheets with 2 different filters (one with reversing prism or mirror) for starters. Now does anybody know of something right off the bat that can be used to dye/color the 2 color records--I've seen the edwal toners--I'm thinking these color the darker portions of the transparencies rather than the highlights--but is that what we want then? If so, I'm thinking I'll buy me some green and red toner and have at it. If I need the clear portions dyed, then would not 2 roscoe filters work sandwiched outside the transparencies?--I get the feeling that you need separate white light sources for each though, right? So that can't possibly work--but that "kodachrome" seemed to work, so I'm thinking there was some kind of a registered screen in there then so you can use the same white light source (light table).

Solantine Pink and Chicago Blue are two dyes that come close to being a usable pair. You need the right filters to match the dye set to expose the film. These would be at about 450 - 500 nm and 600 - 650 nm for starters.

PE