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- 8x10 Format
Kodak matrix film was very special in many ways
No Kodak did not specify all characteristics Separation Negative Type I and II
The matrix film that Bettina Haneke uses didn't come from Ekfe, and is an entirely different formulation optimized for blue laser exposure. And no, it's not available to the public. It's possible that there was a preliminary version which did come from Efke, but I'm not going to dig through my old notes. All this didn't involve investors, but a substantial university grant, unlikely to be repeated. Any serious DT revival is likely going to be reliant on some kind of philanthropic interest.
Kodak materials weren't as consistent as you imply. Towards the end, as the older technicians were being replaced by lesser experienced ones, not only was there a flawed batch of yellow dye which got out (not to mention the flip flop in its variations), but also some lesser quality receiver paper. Matrix film was being coated with especially old machinery.
It really wasn't. It needed special handling because of the unhardened nature of the emulsion, but it was otherwise a very low tech product. In fact that seems to have been part of what killed it off, namely that it would have been very costly to turn it into a highly controlled, efficient and low waste (relatively) modern emulsion. You are confusing the troublesome nature of manufacturing relatively low tech (and high wastage) emulsions and the means employed to try and make them adequately consistent batch-to-batch with them having some sort of properties that you are intent on wishing into existence. They were primitive emulsions by the standards of the 1960s, never mind the 1990s.
It would be visible on the characteristic curve and the spectral sensitivity. Unlike what you assume, the majority market for both materials was not Dye Transfer, and the industrial colour sep market was so vast that Kodak was not the company who dictated who got the secret knowledge. Kodak were however in the business of selling lots of those films, so they sure as hell told customers exactly what it did and didn't do (and quite literally provided lengthy documents about all sorts of masking for offset & other seps that would eventually be screened). On the other hand, maybe the effects of fog on decades expired emulsions are what's distorting your understanding, a bit like how you seem to be desperately trying to get 2+2 to equal 22. Craft based colour separation processes are not particularly tricky processes up until the assembly stage. As long as the seps are correct enough, there are a lot of controls at assembly.
And if you have read Hunt properly, you will see that you are making quite a muddle out of his work, which is well explained and intended to make things clearer for the end user (such as what masks you can dispense with). There are also good (and obvious, so obvious that a glance at the data sheets will tell you) reasons why Sep Neg 1 had benefits over Super-XX, it just requires a little consideration of where Super-XX might hit the wall. There are plenty of current materials that can be co-opted.
But again, don't pretend to speak for me, or discount whom I might have spoken to myself. Lachlan already pointed out some of your inaccurate preconceptions of matrix film manufacture. And it's been cited by numerous experienced practitioners than those you just mentioned, some of whom gained access to Kodak's own formula. It has been reasonably said that matrix film was one of the simplest films to make. The bigger trick would be to make a receiver paper of equal convenience.
In this day and age, any chemical ingredient still extant in trace amounts can be identified and replicated by major R&D labs, or even serious University labs. It happens all the time. DT printing itself just doesn't carry enough financial incentive anymore to entice that kind of sleuthing; and any underlying patents are no doubt long expired. Dye imbibtion films came into existence well before the official era of Eastman dye transfer printing per se. The only thing stopping an even better product from emerging is lack of a market, not the technological hurdle. Kodak was basically just coasting for decades, just like "good enough" inkjet probably will once it plateaus.
One reason legacy products continue on in unchanged form, is that once practitioners mastered certain complex skills, especially those which involved multiple-worker assembly line strategies, it would be clumsy to change, even if component products could be improved. But in this case, all the key film and paper products involved in DT printing simply aren't in production anymore. Go ahead and extol Separation Film type this and that till the end of time - all that is valid in the same sense dinosaur paleontology is - interesting, yes; but you're never going to have your own living breathing Jurassic Park. And I think Lachlan is onto something when he remarked that the alleged self-masking property you think you're seeing is just an artifact of badly outdated film.
Sigh ... 30 yr old film says it all. You're lucky some of the emulsion didn't frill off. Too bad all those "better" films you espouse are unavailable going forward. What's the point? How does that help anyone wanting to get into the game for
themselves?
61 green filters are getting quite hard to find (I have a glass one); but many people got along with a less dense 58. I obtained identical curve results with my onboard green colorhead channel as with either the 61, or 61 and the green channel combined; so the green was quite pure in either case. Likewise with 29 red and my red channel, and 47B blue and the blue channel itself.
So according to you all the separation negatives be given the same development time? There are 3 development times for Super XX pan and 3 different development times for Separation Negative films.The nice thing about TMX100 is that it doesn't have the blue lower gamma issue that Super XX and FP4 do. I never heard of anyone using HP5 for separations, at least in relation to DT work; it has a long toe, and is quite grainy for a modern film. Delta 100 has been used, but only in relation to digital re-profiling.
Nearly entire 8x10 custom cuts of TMax 100 have been devoted to DT separation negs, and repeatedly. That was one of its intended usages right from the beginning; and it was the handwriting on the wall spelling the end of Super-XX,
even though DT itself was axed by Kodak not long after.
And yes, I have been able to develop all 3 seps on TMax for the identical time, or all at the same time, to obtain the same amount of gamma with overlapping curves. It took a fair amount of work to find and fine-tune its sweet spot of reciprocity, where all three coincided. But having done that, it's highly predictable. I was using narrow-band RGB channels, including excellent internal electronic feedback control. I have good reason to believe my own special exposure source is quite superior to the old Condit colored filter system, but spelling out exactly why might be getting nitpicky. (Hint : there are two distinct ways to achieve dichroic narrow-band cutoff). My method is certainly easier to use, and there's no light leakage.
I've never tried this with a conventional YMC colorhead; but if I had to, I would be using glass 29 red, 61 green, and 47B blue filters over the lens, except in the case of Kodachrome, where 25 red is said to work better. But one has to be careful with these specific filters - they vary somewhat between brands, and even within the same brand sometimes when it comes to consistent quality control. I've also measured certain real gel (Wratten) and pseudo-gel filters.
With TM400, however, it's ironically the green separation which needs a little more development. And with all the other films, the blue separation had even more severely reduced gamma. I can't remember how Tech Pan responded, or even where I filed those particular notes, except that it seemed hopeless for critical full-scale separation work. FP4 is the film recommended by Ilford, with its own blue sep mismatch.
I appreciate anyone who aspires to contribute to the revival of such a beautiful process as dye transfer is. But it can be quite frustrating when you refuse to step out of your antique shop and recognize what has been going on in the interim, with respect to both current films and improvements in darkroom equipment.
Many tens of thousand of dollars have passed under the TMax bridge since the 1980's, regardless of a few early naysayers who just didn't want to revise entrenched habits. As they say, you can lead a horse to water, but you can't make it drink. TMX100 has improved since its inception, and no longer shoulders off as readily as it once did.
FP4's commendation for color separations was right up front in their earlier tech sheets. The demand for that kind of usage has fallen off, so the current FP4+ tech sheet merely refers to its numerous applications generically beyond general photography. For decades, Andy Cross has been among those using FP4 and FP4+ for both both DT and color carbon separations.
And my gosh, you sure need to get up to speed on how dichroic filtration actually works in specialized applications. They can be engineered for very clean nm cutoff, superior to conventional filters. I doubt you understood a word I said. You also greatly underestimate my own suite of masking skills. Remember - you don't speak for me, nor for my equipment.
The evenness of my exposing illumination is very precisely measured, as is its intensity and repeatability.
Not really. A neutral tablet can be made by yourself on the type of transparency film you intend to separate. Even Bob Pace might have said this. Some are available commercially as IT8 Q60 tablets. For critical calibration this is very important. It will tell you the actual gamma of your separations with respect to the transparency you are separating.Yes, in an ideal world, you would use a matching dye-based step tablet. But that means that every time you change a dye variable in tablet itself, or in prointng usage, or relative to the color film in play, you've got a whole new ballgame. Chrome film won't even handle that much range, and certainly not symmetrically. And with color neg, you've got very low contrast. Gotta start somewhere on a common-denominator predictable basis.
I don't know how much longer I want to keep up this conversation, if it just keeps going around in endless circles.
But in the meantime, back to an earlier complaint that your Wratten 61 was visibly leaking a lot of red and green light. Well, there's a problem with those in general - they fade over time and with usage. That wouldn't have been the case when new. So you end up with a sliding scale of diminishing quality needing frequent recalibration. More "old stuff" issues.
That ridiculous, it wasn't designed for it.
Any general purpose film will work for continuous tone separations. Kodak recommended Super-XX because it was their general purpose sheet film, in a range where many of their other sheet film products were geared towards very specific markets (an extension of the mentality of 'you push the button, we do the rest'). In contrast, most of Ilford's sheet film products were and are general purpose.
The attached (I've obliterated all identifying information as if you are even vaguely familiar with the relevant literature, you'll be able to identify them) shows you information that seems to be alien to those desperate to impossibilise dye transfer. Sometimes it's a question of the right developer, other times it might have been about an emulsion aimed at the standard choice of developer in a given industry.
I haven't read every post in this thread, some of which is over my head sorry - I'm curious after watching this thread from a distance though what your ultimate objective might be. Are you operating a dye transfer company, or starting one? Are you looking to supply customers with supplies to produce dye transfers? Is this simply an academic exercise? Just curious. Perhaps you already touched on this and I just missed it.No, not any general purpose film will work well for continuous tone separations. For separations of color transparencies each of the three narrow-band spectral exposures needs to be recorded on film as linearly proportional to the dye curves of the transparency. This requires proper spectral sensitivity characteristics, and there must not be any significant non-linearity in the response throughout the entire curve. Manufacturers don't normally publish how the spectral sensitivity changes as a function of exposure. The nonlinear effect of exposure on the spectral sensitivity of Tmax 100 will result in a characteristic curve that is not completely flat for some separations. The red or the green separations exhibit the greatest change in spectral sensitivity characteristics during exposure. According to Kodak Technical Publication F 4016, one can see a change in the normalized spectral sensitivity curve from 0.3 D to 1.0 D. Kodak Separation Negative films and Super XX pan film will keep constant tonal linearity across all wavelengths along the entire curve. Some of these problems with spectral sensitivity have been discussed in Gorokhovskii, General Sensitometry (1965) and Gorokhovskii, Spectral studies of the photographic process, London Focal Press 1965.
I have heard that Ilford FP-4 will work ok although it will give a flat curve at a higher gamma. It probably doesn't have a completely flat curve throughout the entire density range of the transparency. The latest datasheets I have of Super XX pan, indicate it was for some narrow specific markets, perhaps that wasn't always true.
The curve on the left is Ilford Ortho Plus, the middle is a Kodak film that might be Super XX pan in DK-60a with white light exposure, and the one on the right is definitely Super XX pan in HC-110 with white light exposure. Is this to try to say I don't know my curve traces very well, Lachlan? Curves of significance are made using narrow band light, not white light.
I haven't read every post in this thread, some of which is over my head sorry - I'm curious after watching this thread from a distance though what your ultimate objective might be. Are you operating a dye transfer company, or starting one? Are you looking to supply customers with supplies to produce dye transfers? Is this simply an academic exercise? Just curious. Perhaps you already touched on this and I just missed it.
My goal is to support interest in this type of process in the fine art industry.
Gosh, IB, you've sure got you facts mixed up, and seem to be in downright denial. And maybe a typo too - Portra 400 is a popular ordinary color neg film, and like many of them, has a relatively wide "latitude", but certainly not with respect to decent performance way out there in the Kuiper Belt; the realistically usable range is far less.
Super XX had only about I stop more of straight line down into the shadows as TMax films, that's all. And as far as nobody using TMax commercially for DT separation use, well, I'll simply spare you the embarrassment. Frog Prince was a tiny operation, way back when; I'm not referring to them, but to a fully modernized operation still ongoing, at least for awhile more.
What you refer to as Empirical evidently only refers to some kind of sensitometer measured evidence apparently. Well, I've sure done my share of densitometer plots; but the fact is, lovely dye imbibtion were being made before densitometers were even available.
I know you despise the Kodak E80 publication, but the kindly author of that told me that even the old Kodak visual densitometers were plenty adequate for DT work, since there was so much flexibility in the process in the dying and rolling stages. A person could make their own visual comparative densitometer using just a 21-step tablet, a piece of black cardboard with two paper punch quarter inch holes punched in it, and a lightbox. Sneer, if you wish; but they got some pretty darn good prints that manner. I'm all for fine equipment and precise technique; but I don't want it to become a religion - the whole point is to lead you to where the process becomes easier and more spontaneous, not more and more complicated!
I've made sheet film step tablets with every significant type of chrome film I've ever intended to print, and some color neg films too. I've got whole sets of them. But there are many times where a relatively modern non-yellowed Stouffer step tablet gets one from Point A to Point B faster. I hope I don't need to explain that in detail. Kodak even had their far more expensive reference versions. I won't go into how industrial spectrophotometers are themselves calibrated.
I recently sold off my last 75 sheets of 8X10 Tech Pan. I have no more use for it; but I certainly do know what it is good for, and what it is not.
Now back to TMax 100. It is a far better masking film than Pan Masking ever was. Sure, it has an antihalation layer, so you need a supplementary diffusion sheet. But one can get a a very long straight line even at quite low gamma if they have the right developer. I've shared the trick so many times already that there's no sense repeating it here. Even FP4 makes a fine masking film if you know how to handle it analogously.
The one legit complaint about TMX is that when the separation gamma is significantly boosted in combination with a
straight line developer, it can develop a slight reverse "dowagers' hump" in the middle (versus the typical sag). But that's a minor complaint.
I still don't know how you can go forward if you refuse to take into account currently manufactured films. Super-XX,
Color Sep, and Imagesetter films aren't going to come back.
have in mind running this thread through AI and condensing it into maybe one page of practically-oriented information.
Yeah, this would be one of my main concerns, which is why I'd welcome anyone with practical suggestions in this area in particular. I agree we can do without the faff.The main challenge with dye transfer is getting access to the matrix film (from the hoards that have never seemed to use any of the more recent production batches of the stuff) without having to resort to emulsion making/ scaling.
Durhurh. My point is that 5 pages of bickering/diatribe could be condensed into a set of 4 to 8 key arguments/issues, which someone could then take or leave as they desire.Ai won't cure that.
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