Thanks Michael and thanks for explaining the starting point and mol. weight of each. This experiment/project is not at the top of my priority list at the moment and as Ron points out it probably shouldn't be either, but it's still fun and something to do in my elderly years since chasing women and closing bars seems out of the question now. John WJW PHOTO:
If you want to try to use a PPD deriviative such as CD-2 in place of PPD, one logical starting point would be to use a mol/mol weight substitution. As an example:
Mol. weight of PPD: ~108g
Mol. weight of CD-2: ~215g
So you would start out by using approximately 2x the amount of CD-2 (suppose the the formula calls for 5g PPD, you'd start with 10g CD-2).
However you would likely also need to adjust the final pH of the developer when making this kind of substitution. CD-2 is an acid salt as opposed to PPD free base.
Nothing wrong with experimenting of course, but my advice would be to listen to Ron. Really, this is all ancient history - which includes magical formulas such as the infamous 777 with totally unfounded reputations.
Regarding Sigma, they will not sell to us photogs. A while back I tried to open an account with them as legitimately as possible, filled out all the forms etc. No dice.
Yes, my friend has already order that from them. I'll be using PF's Developer 12 as a reference for my mix with the CD-2 when I'm ready to try it.I think this is what you are looking for?
http://stores.photoformulary.com/film-developer-12/
and the data sheet:
http://stores.photoformulary.com/content/01-0210.pdf
Sorry to be late to the party, but there's news:Yes, my friend has already order that from them. I'll be using PF's Developer 12 as a reference for my mix with the CD-2 when I'm ready to try it.
No real argument. Halcyon also has salicylic acid, which is also a factor, and we don't see much in the way of fog, if at all. It's actually an older formula of Jay's, made for modern film. Good stuff!As I mentioned before PPD is a better silver halide solvent than it is a developing agent. Using the older PPD developers may result in dichroic fog with newer fast emulsions. There is a reason why these developers fell out of favor. Think about it.
Any use of a color developer in B&W formulations done years ago are bound to be very primitive based on what can be done. I would dismiss them entirely for any useful purpose. Remember that there is no magic bullet (unless a NEW approach is taken).
PE
Hence the use of ascorbic and salicylic acids, along with the PPD--an approach not tried prior to Halcyon.I did not say they were inferior.
I said that the experiments and use years ago were very primitive based on current knowledge (at EK and other companies).
PE
As I remember MCM 100 uses in a veryI bought PPD from Photographers Formulary, 3 or 4 years ago, might have additional restriction on selling bulk, I hope it does not become too expenwsive as it is used MCM 100 my current go to developer.
An old friend and I were talking about film developers and he mentioned that he wished he could get his hands on Edwal's 12 film developer again. He said it was one of his favorites from years gone bye and now he wants to start doing his own developing and printing again. I told him he could mix his own with chems from Photographers Formulary or just buy their ready made Developer 12. I told him if he bought the chemicals (I gave him the recipe from the cookbook) he could use my scales and magnetic stirrer to make his batch. He emailed me a couple of days later and said you can't buy PPD (p-Phenylenediamine) at Photographers Formulary and bought the Developer 12 mix instead. I was curious and checked myself and he was right. I then started looking for a place to buy it and came up empty handed. Does anyone no where to buy PPD? Also, I remember Gerald Koch, I think, saying something about color developer CD-1 or CD-2 could be used instead of PPD. What about P-Aminophenol Hydrochloride as a substitute?
Hence the use of ascorbic and salicylic acids, along with the PPD--an approach not tried prior to Halcyon.
As I remember MCM 100 uses in a very
simple formular additional metol.
And as a result of this combination it is an absolute finest grain developer.
Or have I mixed up some facts? And thats wrong?
The developer I meant is the original from the 30th may be it is older.
They changes a little the amound of
metol but the basis was the combination
with paraphenyle diamine.
MCM 100 was the original - or not ?
Johnsons - just comming in mind -
yes Johnson was the company wich
creates it out of older formulations.
with regards
I did not say they were inferior.
I said that the experiments and use years ago were very primitive based on current knowledge (at EK and other companies).
PE
Salicylic acid and similar were used with PPD many years ago, definitely before WWII so not a new approach at all.
Johnsons used their own developing agent Meritol which was a fusion of PPD and Pyrocatechin.
Ian
I did not say they were inferior.
I said that the experiments and use years ago were very primitive based on current knowledge (at EK and other companies).
PE
I did not say they were inferior.
I said that the experiments and use years ago were very primitive based on current knowledge (at EK and other companies).
PE
PPDs can be used with other ingredients to give good speed, contrast and grain. As noted above, some addenda gave quite good developers. PPDs often did not need auxiliary developers.
PE
Comming back to my question above.I'm sure you are expert in this, but I have seen very fine grain and excellent sharpness from such developers.
PE
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