Modern Rodinal Substitutes

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Originally Posted by billtroop

and anyone who wants to know who Dr Shneour is has only to look him up on Google.

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I kept thinking that name looked familiar. I've seen it in Skeptical Inquirer magazine, a favorite of mine.

Dr. Elie A. Shneour, is a biophysicist, the research director and head of the Biosystems Research Institute, the former chair and still member of the San Diego County Science Advisory Board, the author of numerous research and lay articles as well as several books. He serves in national level scientific capacities, is a member of a number of scientific societies, a founding chair of SDARI, and a CSICOP Fellow.
http://sdari.org/event-archives-04.html

So he has no actual connection with Agfa, but he simply did an analyis of the product...

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Originally Posted by gainer

The batch I made yesterday is already showing signs of weakness. Two things come to mind. The water I used undoubtedly contained oxygen in solution.

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Pat - oxygen saturated water at 20C only contains 9.2 mg/L oxygen. First off, that's not much. Second, you can remove it by adding a pinch of sulfite to the water before dissolving they rest of your ingredients.

Well, after some literature searching I find that you probably will not be able to make a stable Rodinal like concentrate from Metol. It is more active than pAP, enough so that the concentrate will probably not keep. Otherwise, the two compounds are quite similar differing only in the N-methy group in Metol.

PE

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Originally Posted by Photo Engineer

Well, after some literature searching I find that you probably will not be able to make a stable Rodinal like concentrate from Metol. It is more active than pAP, enough so that the concentrate will probably not keep. Otherwise, the two compounds are quite similar differing only in the N-methy group in Metol.

PE

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And the form of the salt :D

Only Edmund Lowe used the sulphate form of p-Aminophenol

Ian

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Originally Posted by Ian Grant

And the form of the salt :D

Only Edmund Lowe used the sulphate form of p-Aminophenol

Ian

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The form of the salt is irrelevant in terms of keeping. The acid used to make the salt is probably only important in terms of the effect of the Chloride ion on development of some emulsions as I mentioned earlier.

PE

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Originally Posted by Kirk Keyes

Pat - oxygen saturated water at 20C only contains 9.2 mg/L oxygen. First off, that's not much. Second, you can remove it by adding a pinch of sulfite to the water before dissolving they rest of your ingredients.

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A pinch? I thought that was against your religion. How many milligrams in a pinch?:p

If I add anything before the metol, it will be a little ascorbic acid. That is to assure that any oxidized Metol that might be in my supply will be regenerated before I add the sulfite.

I did just that a while ago. Metol, a healthy pinch of ascorbic acid, then enough KOH to form the Potassium Metolate. The usual usual flocculent precipitate never showed so I added sulfite. I still have only sodium.

The resultig solution had little or no color. (my eyes are 82 years old, so I may not see the yellow end as well as some of you young squirts.) I did a test strip on EDU 400 Ultra. Not the best subject in the World, but it makes me want to go sit in that chair.

P.S.
8 minutes, 68 F, 1+25 seems to be a good starting place for this film.

After looking at Dr Shneour's credentials on the internet, and confirming with Bill Troop that this was indeed the same person, I come to the conclusion that he is indeed a respected individual in US chemistry circles with good credentials. I also find that Bill, at no point, said that Shenour was associated with Agfa.

Therefore, Doctor Shneour's comments may be considered entirely valid as given to Bill in an interview. Any comments to the contrary may be irellevant. Dr. Shneour has been free to comment since the publication of the original FDC and has not done so and therefore I consider the matter closed as stands in Bill's comments.

PE

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Originally Posted by Ian Grant

Ron, no-one is casting any doubts on Schneour's abilities or credentials, lets make that 100% clear. What I'm questioning is Bill Troop's use of his name in the FDC, when clearly none of us had ever heard of him in connection with Rodinal or any other developer.

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That's interesting, as I've apperently misunderstood the sentence in the FDC too!

"Dr. Elie Schneour believes that the differences are not photographically significant."

Dr Schneour's name was just blurted out in the book with no reference as far as I can see as to exactly who he is. One is left to beleive that he's an Agfa employee or some sort of Agfa insider. The only hint that may be otherwise is that he is listed in the acknoledgements as "researcher/photographer"...

Instead, we find he's a guy that did a "spectrographic" analysis. That's a rather broad "type" of analysis.

Bill, could you tell us more details on Dr. Schneour's analsis? Was it with IR, FTIR, UV, or Visible light? Was it an atomic absorption spectrophotometer or an inductively coupled plasma spectrophotometer? Did he analyze for anions as well, or just cations?

By the way, I did an analysis for Total Organic Carbon and Ion Chromatography for anions for XTOL when it came out. Interested in the results of that? You can quote me in the next edition!

This thread is already very complicated and hard to follow. At least for me.

I find this bickering very annoying.