Can anyone chime in about its solvency characteristics? Maybe comparing with other solvents..
In my experiment, TEA did dissolved Silver Chloride. but not Silver Bromide. I would therefore rank it somewhere with Ammonia, and its solvent property is, of course, dependent on concentration.
Is it as effective as Ammonia in dissolving silver chloride?
That was my impression during my test. Please note, that this was just a quick experiment to prove/disprove the old claim "TEA is not a silver solvent". No quantitative data was obtained during this test. Please also note, that different batches of TEA may behave very differently for reasons already mentioned.
If it works as good as 2% ammonia in dissolving silver chloride then it can perhaps replace the former in B&W reversal processing workflow that uses copper sulphate as the bleach. Might not be as cheap as ammonia, but more convenient and less hazardous.
The advantage of Ammonia is, that it will not form a precipitate with copper ions. If you do this with TEA, you'd have to control its pH carefully.
After the copper sulphate bleach step and before the TEA bath, the film is given a through wash which is followed by a clearing bath in 5% sulphite and a water rinse. Will there be any residual copper ions in the film after this?
My impression is, that Bill still favors Metol very much over Phenidone, this would explain his reluctance to include PC TEA and 510 pyro. One should also consider, that PC TEA is said to lose half or even a whole stop of light, which is not very impressive as far as modern developers are concerned.
Not sure about his stance on TEA.
So what do you believe causes Troop and Anchell to exclude TEA and Pyro 510?
Thanks
pentaxuser
I don't know why Troop and Anchell excluded PC-TEA and Pyro-510, especially since Anchell included them in his solo book. Some may be skeptical of developers that amateurs formulate. This brings up a bigger issue with current state of analog photography. Early photographers typically made up their own chemistry in a kitchen-sink fashion. Then large manufactures took the lead in photochemistry, although there were ongoing contributions by individuals.
But in the 1990's the large players, like the Wooly Mammoths, departed the scene. Now it is amateurs and small firms that are the innovators. In some ways we have gone full circle back to the ways of early photographers. Amateurs and small firms are at a disadvantage compared to the likes of the former Kodak which invites skepticism about their efforts, which is not entirely unjustified. One response to this situation is to say that nobody will every create anything better than the big boys did so one should will stay with their tried and true products forever.
Another response is to see the progress in chemistry being made, despite the limitations, as a positive thing. The original formula that D-76 was based upon likely had some rough edges and was not as fine grained. But Kodak refined it over a period of years to arrive at D-76. Contrary to what one might think, Kodak probably did not view the standard version of D-76 as something that could not be improved. In a similar way, PC-TEA and Gainer's other ascorbate experiments were a great achievement at the time. But they also have some rough edges. There is a lot of potential for improvement in that style of developer.
The Photo Engineer knew the immense RD capability of Eastman Kodak and how difficult it would be to match that. He had plenty of reason to say there was no point in amateurs trying to create new chemistry. But he encouraged experimentation and there is no point to experimentation if there is no possibly of creating something new and useful. One reason to publish formulas like PC-TEA and 510 Pyro is that it may inspire people to create new and better formulas.
Can anyone chime in about its solvency characteristics? Maybe comparing with other solvents..
I never knew that Wooly Mammoths developed and printed film. Learn something new every day.
It would seem odd that Anchell and Troop excluded PC-TEA and 510 purely because they held them in contempt. Anchell, in his Darkroom Cookbook 3rd ed. pp. 29-30, not only includes them, but highlights Gainer's formulas more than many developers.So it would seem,from what is being said by various posters, that Anchell and Troop have excluded those developers which they regard as inferior or otherwise less reliable? Is that a fair assumption on my part? If it is not a fair assumption then exactly what is it that causes them to exclude TEA and 510 Pyro?
It may be reasonable to state that a drawback of 510 Pyro is that it stains the reels compared to other staining developers but is this really the case?
John Finch of Pictorial Planet fame has done videos on 510 Pyro as have others and while I haven't seen all the 510 videos I have seen a few and nowhere does he even hint at the staining of the reels, nor can I recall others mentioning it. From what I have seen of his many videos he is normally very careful about covering all aspects and I'd have thought that serious staining deserved at least a mention
So is the staining such that the normal washing of the reels after the process is finished is insufficient to remove it?
Thanks
pentaxuser
It would seem odd that Anchell and Troop excluded PC-TEA and 510 purely because they held them in contempt. Anchell, in his Darkroom Cookbook 3rd ed. pp. 29-30, not only includes them, but highlights Gainer's formulas more than many developers.
The intended audience for Anchell's book clearly seems to include do-it-yourselfers that might want to tinker with formulas. He says,'The Darkroom Cookbook is meant to be a point of departure for photographers desiring to take control of their craft. At any time, you should feel empowered to "interpret" any formula, design a new one, or adapt and existing one to a new purpose.' He then goes on with suggestions on how to do that. So the book is not just for people that want to use bulletproof established formulas just as they are. The organic solvent developers like PC-TEA, even if they are not perfectly refined, ought to be listed in such a book because they represent an important innovation in the history of photo chemistry, and may hold lot of potential for improvement. I suspect that is why Anchell gave them prominence in his book. I am looking forward to trying Relistan's new PC-510 because it may be an example of an improved organic solvent developer.
FX-37 has 60 g/L of sulfate and is often referred to as a low-solvent/acutance developer.
Page 81 of the FDC2 says, "Dilute 1:3." Thus, FX-37 is regarded as a non-solvent developer because it is expected to be diluted 1+3, yielding 15 g/L of sulfite.
Mark
Here is my take on this: it was "common knowledge" for a long time, that TEA has "no solvent properties", while some folks disputed this. In order to settle this for myself, I did an experiment with TEA, Silver Nitrate and alkali halogenides. My TEA batch is from Fototechnik Suvatlar and of 99% purity.
In my experiment, TEA did dissolved Silver Chloride. but not Silver Bromide. I would therefore rank it somewhere with Ammonia, and its solvent property is, of course, dependent on concentration.
HOWEVER: as has been stated here, the solvent property of my batch may or may not be due to the TEA itself. The remaining 1% are, as always, a mystery, and may well comprise DEA or MEA, which were always known as silver solvents.
Therefore: even if TEA is not a silver solvent, your batch of TEA may well be. YMMV dependent on source of TEA and on amount used in your product.
Before Gainer created PC-TEA, he devised a variety of ascorbate developers mixed in water. Others have also created ones like these. There is also PC-Glycol. If TEA is to be blamed for PC-TEA's loss of film speed, does that mean that the other sulfite-free ascorbate developers that do not use TEA feature higher film speeds?
If PC-TEA suffers from an excessive solvent effect due to TEA, does that mean a variant of PC-Glycol with a similar alkali would have noticeable less solvent effect?
https://unblinkingeye.com/Articles/VitC/vitc.html
Neither PC-TEA nor PC-Glycol (which I used a lot) reach box speed. This was one of the reasons that I worked on PC-512 Borax. It is not very solvent, at least with bromo-iodide emulsions it seems. And the pH drift may be the other part of the reason.
I don’t think you’ll see much evidence of solvency in PC-TEA.
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