Ian Grant
Allowing Ads
The problem is a touch of Pyrogallol would materially change the developer characteristics particularly when fresh with no oxidation. If it was Pyrogallol going black in Rodinal it would do theis very quickly, days not many months once the bottle was opened and partially full.
Getting away from Perceptol for a second - Is anyone ever going to find out the results of Dr. Schneour's analysis of Rodinal? Or is that going to remain a secret?
Much of it was in the thread Modern Rodinal substitutes.
Agfa have always said they've never published any of the Rodinal formula...
So in the article "Modern Rodinal Substitutes" I suggested how I'd make substitutes for Rodinal and detailed why I'd chosen those particular formulae.
Ian
Since those 2 sites in PG are meta to the central OH, the activity of the sites is probably low. I would have to look this all up, really to be sure. It is just conjecture right now from old organic chemistry.
Calling Calbe R-09 formula a "pre-WW II" formula is confusing to me as well, since, as I understand it, it can also be called a WW-II formula.
As for as Nitrogen, was there any official AGFA or Calbe for that matter mention or discussion of this?
Maybe I am guilty for not reading everything here on apug - again.
Sorry if I am lowering the curve, but for example with nitrogen, the only thing I could quickly turn up were a few suggestions and not documented Agfa policy. Perhaps there are patents, or inside info, but whatever, I am just trying to follow the conversation not stall it. Please continue!
What am I missing out on by not using Microdol X or Perceptol??
I would like to go back to the original question--which I think remains unanswered:
Has anyone tried comparing `Edgar Hyman`s Microdol substitute formula with Ilford Perceptol? If so, did you notice any difference between the packaged product and the home made developer?
Edgar Hyman’s Microdol Substitute Formula:
Metol....................................5 grams
Sodium Sulphite, anhydrous........100 grams
Sodium Chloride (iodine-free)... 30 grams
Water to make.......................1 litre of stock solution.
For me this is not an idle question. I use this formula, which is also Troop's Film Developing Cookbook formula. I dilute 1:4 with water and develop 100TMX. What am I missing out on by not using Microdol X or Perceptol??
From the patent by Richard W Henn:I've tested the formula, it worked well and as expected - much finer grain, drop in effective EI etc, my reply is on the first page of the thread. Since Kodak re-formulated Microdol as Microdol-X and Ilford replaced ID-48 with Perceptol B&W films have changed significantly and those I've used are far less prone to Dichroic fog.
Ian
I'm not a scientist either, but I've used this formula with TMX, 400TX, APX100 and Rollei Retro 80S. I never had a problem with dichroic fog. The results were always very nice.I am by no means a scientist, so I apologize if this question is lame. I have read through this now somewhat old thread. Would a restrainer such as benzotriazole assist in retarding dichroic fog?
PE, do you regard 1970's era ANSCO film as "modern"? And at any event, would BZT help with dichroic fog?
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