Making Commercial Color Separation Negatives of Transparencies for the Kodak Dye Transfer Process

[IB Photochemistry]

It is definitely faster than having to make masks and separation negatives with film. My goal is to be able to make separation negatives to project onto a matrix film. I have been fighting with trying to make separation negatives and masks from 35mm transparencies and a process like this would really make life easier. Thanks for your reply.

Gord, have you used any of the methods for making photographic separation negatives I posted here? I hope they can be helpful to people interested in this approach. Its good to hear someone else interested in making DT prints on here.

 

[IB Photochemistry]

The best DT work I've ever personally seen was that of John Wawrzonek.

He probably used a shadow contrast increase mask with the separations, either as a “black” mask made to be exposed in contact with the pan masking film and separation negative for the CRM, or off an intermediate interpositive. I believe he was using Separation Negative films.

 

[DREW WILEY]

I forgot to mention that in terms of intermediate highlight masking, it's often a lot easier and certainly more cost effective simply to do it via manual shading on a frosted slip sheet, or on the base of the film
back when retouch tooth was common, at least with sheet films having sufficient surface area. It's fairly easy to transfer that kind of skill set over from a Ciba or even a Graphics prepress background to DT, or visa versa. I did a lot of selective bleaching of silver masks using dilute Farmer's Reducer.

I see that David Doubley's site is still up, filled with all kinds of traditional DT info, including pan matrix use. He made the site non-downloadable, and with a finite span of availability. If that's still the case, those interested absorb what you can. He once offered all this in handbook form; I don't know if any copies are left.

There are all kinds of web and even in-print resources on making hybrid masks,separations, and enlarged contact printing negs using Pictorio film etc. I won't go into the pros and cons, and will stick with an all-darkroom workflow for this particular thread. It's also entirely feasible to make color separations from digital camera shots - again, a topic best discussed under hybrid technique, and not here. I'm as guilty as anyone else when it comes to wandering off-topic; but that could be especially confusing in this case.

 

[koraks]

All chromogenic color materials, E6 films, RA-4 papers, and color reversal papers, have internal color masking for correction of their OWN DYES.

This is very much incorrect. RA4 for instance has masking whatsoever. But it's inconsequential as the dyes in chromogenic films (what's in a name!) are fundamentally different from dyes used in dye transfer, where no coupler technology is involved. So my recommendation would be to drop the tangent of dyes in chromogenic films as it has no relevance to a discussion of dye transfer. This will also avoid the unnecessary complication of confusion between internal masking in color negative film vs. 'masking' as a result of inter-layer effects within the film during processing vs. masking as it's done during printing with external/physical masks manually exposed from an original (or today, inkjet printed). Only the latter is relevant in this discussion and for a variety of reasons, it's just not very useful to include chromogenic materials into this discussion.

I will soon post some examples of some Dye Transfer prints I rolled myself, some of my equipment used, and separation negatives, and masks.

I would very much welcome this; I also think it would be relevant/interesting for a wider audience than the present, small circle of discussants in this thread. I would also consider (recommend) to start a new thread for this purpose, which might focus on practical comments on the basics of the dye transfer process as you practice it.

 

[koraks]

Moderator note: this discussion has for some time now been quite fierce, and in itself this is not something that warrants intervention. However, at times, it borders on name-calling and other forms of disrespectful behavior. Please refrain from such behavior and keep the exchange civil. Thank you.

 

[koraks]

I see that David Doubley's site is still up, filled with all kinds of traditional DT info, including pan matrix use. He made the site non-downloadable, and with a finite span of availability. If that's still the case, those interested absorb what you can. He once offered all this in handbook form; I don't know if any copies are left.

Thanks for the tip; IDK what the bit about 'non-downloadable' was about, but everything seems to be there and easily downloadable. It's found here: http://daviddoubley.com/DyeTransfer.htm

 

[Lachlan Young]

Pan Matrix 4149 was a 1960's emulsion, it had another designation before that. Kodak decided to discontinue it a few years before Dye Transfer was discontinued; it had nothing to do with “lack of sophistication”.

You've been beating this dead horse into dust for decades and it'll never be what your fantasies want it to have been.

It was not a sophisticated product, and that made it harder to manufacture as outright material wastage (consequent with shrinking demand) became a real factor. The one difference in practical terms between what Kodak made and something like the Browning emulsion, is that Kodak had achieved a degree more monodispersity in grain structure. But that's the difference between a 1940s emulsion and a 1950s emulsion, nothing newer. Trying to equivocate and swivel around on the matter of sensitising dyes (of course Kodak's would have picked something reasonably close for a colour neg film of the era it was designed in) or depth effect dyes/ pigment dispersion (depth effect control is not a million miles away from anti-halation or dealing with internal reflections) belies how little you really know about the basics of what the emulsion needs to do. In terms of the needed speed/ grain and other emulsion characteristics required to make the gelatin matrix work, something close to Super-XX would have made enormous sense for Pan-Matrix.

Anyway, there's no point in continuing this any further as you have never seemingly had any interest in the practical material reality of the product, but rather in confecting the former dye transfer industry into some sort of closed shop of secret knowledge intimately tied to Kodak, rather than as a group of highly skilled craftspeople who readily borrowed techniques from their graphic arts colleagues as and where necessary to get jobs out the door, and with colours/ tone scales that made the relevant art director happy. Most of the people I've encountered who work or worked in colour separation by analogue means have given very freely of their knowledge. As I said earlier, the real skill is in the assembly step.

 

[IB Photochemistry]

To respond to koraks on my use of the term “internal masking” or “masking” of chromogenic materials, I probably should have used the terms Interimage Effects, so as to avoid confusion. Interimage Effects occur in chromogenic materials but most of that is beyond the scope of this thread. They act like an “internal mask” but are not masks added in the printing stage. They are of significance for color separation of transparencies since they tell us how transparency dyes create neutral. For example, if we take the spectral density of each of the three E6 transparency dyes individually and want to create neutral we can't add all three of them in equal quantities. Cyan has too much magenta contamination, magenta has too much yellow, and yellow has a little too much magenta. Doing so would result in an unbalanced neutral, so the interimage effects reduce the contrast of the magenta, and yellow dyes, so the neutral has the same density as the primaries individually. The neutral of a transparency has an Equivalent Neutral Density at around 5000K to be compliant with ISO standards.

All color accuracy from a transparency (or other color system) comes from its ability to create a balanced neutral. Excellent color requires excellent neutral. The E.N.D. standard has been used for characterizing the quality of color materials.

This is important to know when we analyze the curve traces of separation negatives. The cyan, magenta, yellow, and neutral curve traces on the separation negatives obey the Interimage Effects of the transparency and that of the masks that we add during the separation negative exposure process. An example is, a separation negative of an unmasked transparency will have the same contrast in the neutral density steps, as the magenta density steps. By adding a red principle mask to the green separation negative, the magenta has roughly the same contrast but the contrast of the neutral curve trace is reduced by the percentage of the red principle mask.

 

[koraks]

To respond to koraks on my use of the term “internal masking” or “masking” of chromogenic materials, I probably should have used the terms Interimage Effects, so as to avoid confusion.

Thanks; yes, these effects play a big role in E6, C41 and ECN2 film. But I'm frankly not so sure (at all) that they also are exploited at any significant scale in RA4 paper. I've not heard about it and what I have heard/know about modern RA4 paper does not seem to imply it or make it very plausible. Anyway, we agree that this (inter-layer/image effects in chromogenic materials) is somewhat of a tangent. An interesting one, but we should reserve it for a different thread, IMO.

 

[DREW WILEY]

It's quite apparent to anyone who has worked a lot with a variety of them, that few if any chrome films were ever truly neutral. And they differed from one another with respect to specific anomalies. (Fuji Astia had the most neutral balance of any of them; Kodachrome was reasonably well balanced, but hardly ideal.) And no print media itself is ideal. Dye transfer allowed a considerable degree of correction or manipulation, but at the cost of a lot of time and materials. Modern digital manipulation simplifies a lot of that, but still can't overcome inherent limitations in the output medium itself. Inkjet can be especially disappointing in terms of gamut quirks and limitations.

That's why no "one shoe size fits all" approach to masking works well except in those instances it was specifically tailored for.

At a certain point you can't fight against it, and just have to learn to dance with your chosen medium, and let it lead.

 

[IB Photochemistry]

You've been beating this dead horse into dust for decades and it'll never be what your fantasies want it to have been.

It was not a sophisticated product, and that made it harder to manufacture as outright material wastage (consequent with shrinking demand) became a real factor. The one difference in practical terms between what Kodak made and something like the Browning emulsion, is that Kodak had achieved a degree more monodispersity in grain structure. But that's the difference between a 1940s emulsion and a 1950s emulsion, nothing newer. Trying to equivocate and swivel around on the matter of sensitising dyes (of course Kodak's would have picked something reasonably close for a colour neg film of the era it was designed in) or depth effect dyes/ pigment dispersion (depth effect control is not a million miles away from anti-halation or dealing with internal reflections) belies how little you really know about the basics of what the emulsion needs to do. In terms of the needed speed/ grain and other emulsion characteristics required to make the gelatin matrix work, something close to Super-XX would have made enormous sense for Pan-Matrix.

I completely understand how the use of an extinction filter dye will produce an exposure modulated relief image. I can say with certainty it was NOT unhardened Super XX pan. I have measured sensitivity at 700 nm, which as you might know Super XX really has no good sensitivity there. I couldn't make a red interpostive of Ektacolor film using Super XX pan. Kodak Separation Negative film has poor sensitivity for the C-41 cyan dye as well. I think the spectral dye peaks of color negative dyes were very similar to those of the 1940's, but I haven’t looked at all types of chromogenic dyes from the era but I suspect they are very similar spectrally to the C-41 dyes used now. Its a bit off topic but I thought I should address it.

 

[IB Photochemistry]

One can argue the about the skill in assembling a final DT print, and there is some craft to that. I have done (and still practice) it fairly well myself. Without good separation negatives it is nearly impossible to make a high quality print. The rinse controls effect density and highlight density, and controlling dye acidity effects contrast. Other kinds of controls are possible for retouching, to printing more than 3 matrices. Controlling this required information that wasn't published and was regarded as a trade secret. Unless someone can cite a particular publication where sensitometric control of DT is discussed, I will continue to insist that everything from making the separations, matrices, and pulling prints was a Kodak trade secret.

While I once believe what that the commercial labs borrowed knowledge from the graphic arts industry, it became apparent to me that some of these techniques were completely unknown in the graphic arts field but known to the DT industry. The kinds of highlight masks used, color isolation techniques, mask exposure factors, etc. do not seem to have much application in the graphic arts. And if someone can cite some sources where these kinds of techniques appear I will definitely look into it. The evidence I have, suggests these were mainly photographic techniques and would not be useful for half tone 4 color reproduction.

Prior to 1970 and the Kodak Marketing Education Center, DT labs relied on some kind of technical support from Kodak, probably from the Dye Transfer department. I have papers from archives, that Bob Speck was the main technical contact for professional labs in the 1960's and probably prior. So far I haven't had much success finding a collection of papers from Bob Speck, detailing his role as a research technician and in the marketing of Dye Transfer. From the sources I have Bob Speck retired from Eastman Kodak in 1978. Possibly there are people reading this thread who have worked with Speck at Kodak, that they might be willing to share their experience.

 

[IB Photochemistry]

I have never tried to separate Kodachrome film myself. From what I have heard its more difficult to separate than chromogenic films. The E-80 manual recommends one use the green principle mask on the red separation negative. This has the effect of removing cyan from the magenta. Remember, principle masks don't isolate the dyes, so they will mostly effect the dyes in the print. This E-80 method for Kodachrome probably doesn't work very well either. Bob Pace published another method for separating Kodachrome and I don't know how well that worked. There were some very high end DT labs that could separate Kodachrome very well and make a good print from it.

Commercial labs mostly used a mask made from either an orange 23A filter (with Separation Neg. film), red/green, or 60% red/25%green/15%blue principle mask on the red separation negative. The purpose of using a red light mask on a red light separation negative, is to allow further development of the red separation negative. Only one publication I am aware of mentions this Color Separation Negatives, Phillip Jenkins 1957, and no DT related publications I can find do either. Emulsions like Super XX pan as well as Separation Negative don't have the full-scale tone curve at the same contrast as the other 2 separation negatives, so some additional development contrast is needed. This means all three negatives get different development times. One needs to compensate for the contrast reduction of the red light containing mask with the red separation, so the neutral scale of the transparency curve has the same gamma as the other two separation negative curves.

There is the issue of how well a transparency film reproduces neutral and how well it captures neutrals. This is two different problems. The ability to make neutral is a function of the interimage effects for the particular emulsion. Whereas capturing neutrals well is more dependent on its spectral sensitivity. In my opinion Ektachrome EPN was the most neutral in color reproduction but Fuji Astia 100 was also very neutral but suited more for the portraiture market. In the case for generating a good diffuse visual neutral at an Equivalent Neutral Density at 5000K, most (probably all) E6 films are capable of doing this. The ability of the interimage effects to create neutral allows for color accuracy and standardization. Its possible to make improvements on the color reproduction of the transparency as well, using the masking techniques I have discussed here.