Processing 510 Pyro & 100TMX with Jobo CPP-2

[interneg]

Can't argue against the obvious possibility of Kodak and other labs having investigated the potential of pyrogallol and catechol developers in the light of works such as Levy's.

I think you're underestimating Marilyn Levy's influence - she chaired the SPSE's Processing Section at that time & was on the editorial boards of their journals - and was a very senior civil servant research scientist working for the US military - the self same institution whom Kodak also had deep ties with (& who effectively funded a great deal of basic science research at Kodak) - in other words, her peers at Kodak will have more than likely thoroughly investigated for themselves at the peer review stage. But you also have to remember that Levy was effectively working in specific applied fields rather than more basic research - which is where Kodak had much greater institutional depth - in other words, KRL was finding out about things like HQMS and its effects (and that AA can be used to achieve similar ends). The biggest problem is that people don't realise that most of the effects of 510-Pyro (for example) aren't coming from the pyrogallol, but from what could be achieved by building a suitable phenidone-ascorbate (or HQ or HQMS) relationship - the developer that is known to produce very intense adjacency effects is a later (1967) invention of Levy's (POTA - named after her workplace) - and those effects are from Phenidone alone (Kodak research seems to have been very aware of this soon after). Add a small amount of HQ, HQMS, AA (or probably just about any other source of semi-quinone) and the faults of POTA resolve themselves while leaving a potentially extremely high adjacency effect (from development inhibition effects) - and that same development inhibition effect modulates the Dmax at the same time (which is what seems to play a significant role in enabling POTA to deal with extreme brightness ranges). The bigger problem is that by cranking the definition up too high, your visual granularity also rapidly accelerates - and that is where balancing granularity against the various forms of sharpness enhancement have to be juggled to deliver adequately visually consistent results at 2x or 20x (to take an example), rather than visual granularity plotting like a rocket launch above 5x.

Even the new lab researched developer products like those of Spur also seem to have avoided pyro.

Spur (and Moersch) seem to be a strange combination of quite up-to-date science - modern sequestrants, HQMS, quite a bit of evidence of some understanding of electron pump (vs 'superadditive') developer designs & sometimes questionable choices of primary developing agent(s). There does seem to be a degree of awareness too about how the characteristics of phenidones (Dimezone-S in particular) can be exploited.

[Michael Kadillak]

Sulphite = not a staining developer. Levy's work was not driven by pictorial/ aesthetic requirement, but primarily by military/ scientific research need. And if Levy was looking at those recipes, Kodak will have looked at them too. Everyone was trying to improve on D-76 (and understand its mechanisms) for various reasons, but kept falling at the point they had to do double blind print comparison tests. Methods of dealing with AA's Fenton reaction issues were being intensely researched throughout this period - had DTPA or similarly powerful sequestrant been readily available at the time, AA would have come into use industrially in photochemistry in the 1960s/70s if not earlier. It's clear (from later documentation) that Kodak resolved the mechanism of Levy's POTA without disclosing it at the time - and used that knowledge (as did their competitors who were no slouches in the basic science) together with what they seem to have learnt about HQMS' effects (similar behaviour happens with AA, hence it being attractive as an HQ replacement) being preferential to all the other alternatives. A research result does not necessarily equal a viable/ reliable product - but it can count as prior art, and it's worth noting that Levy's earlier work with thickened monobaths was likely patented defensively against Polaroid (and potentially Kodak). And as for TEA, it was used in Dye Transfer at the time (and other processes etc) so it will definitely have been gone over rather thoroughly by Henn etc in getting to HC-110 (along with lots of other permutations that likely failed the desired parameters) - don't assume you are discovering anything new, and rather than desperately trying to dredge up post-facto defences of not-very-well-thought-out staining developers, you could take a few minutes to consider the nature of large scale photographic research at that time of that article - had there been enough evidence that under rigorous visual test conditions pyrogallol really had advantages over HQ or AA, there would have been concerted efforts to make use of it. Instead, Kodak were patenting ways to eliminate it from the process that relied on it - via the use of Dimezone-S and AA. Contemplate why that might have been.

Well since this rather bizarre dialog started with you pushing research versus actual realized print results as it relates to the utilization of pyro, I have been to the field three times and made 15 quality 8x10 negatives (made 6 negatives today that I will process tomorrow) all that will be processed with pyro that look simply marvelous. There comes a point in time where the legitimate objective of making high quality prints eventually supersedes this meaningless crap from the research department. This is a photographic forum, not a research forum. People post images they made with their cameras and could give a crap about a wide range of experiments that have no bearing on someone pursuing their visual craft. to the best of their ability. As a result I am tapping out.

[tundra]

Well since this rather bizarre dialog started with you pushing research versus actual realized print results as it relates to the utilization of pyro, I have been to the field three times and made 15 quality 8x10 negatives (made 6 negatives today that I will process tomorrow) all that will be processed with pyro that look simply marvelous. There comes a point in time where the legitimate objective of making high quality prints eventually supersedes this meaningless crap from the research department. This is a photographic forum, not a research forum. People post images they made with their cameras and could give a crap about a wide range of experiments that have no bearing on someone pursuing their visual craft. to the best of their ability. As a result I am tapping out.

What???? Your actual images don't listen to the theoretical woulda/coulda/shoulda analysis? The very idea.

For the record, I do see great value in sensiometry and photochemical research. Both were- and are important to maintain the craft. But the map and the territory ain't the same thing...