That looks like what I got when I tried it out. No true colors ,but shades of red-orange instead
Originally Posted by Prof_Pixel
You're absolutely correct!
Originally Posted by Swellastic
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
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 O_o
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?
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Originally Posted by holmburgers
You can find the entire BJP vol 58 at http://ia700508.us.archive.org/14/it...58londuoft.pdf
It's over 100mb
Edit: I see holmburgers also tracked it down while I was looking and downloading it.
Last edited by Prof_Pixel; 05-08-2012 at 03:39 PM. Click to view previous post history.
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/in▓ 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 diazo sensitizers (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 (1 potato, 2 potato) 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.
Originally Posted by Prof_Pixel
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).
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.