I used sodium bisulfite in the Rollo-TEA formula because, 1) the original Rollo Pyro formula contained sodium bisulfite and part of my purpose in suggesting the Rollo-TEA formula was simply to show that some existing formulas, if mixed in TEA, would give essentially the same results as some of the TEA-based formulas being hyped at the time, and 2) I knew from my own testing that a small amount of sulfite is important in the synergism between pyrogallol and phenidone.
Originally Posted by craigclu
BTW, I recently developed about fifteeen 12X20 negatives from a recent trip out west in the original Rollo-TEA solution that I mixed sometime in the spring of 2004, and the results were outstanding. Which points out one of the advantages of mixing solutions in TEA (and glycol), in that you know that they will be good for years and years.
Well, all this talk has made me want to do some developer experiments that have been on the back burner for a few months. So I decided to pull out my electronic balance that measures down to 0.01 accuracy since some of the tests will require very accurate measurments.
Originally Posted by Tom Hoskinson
Guess what. The scale is gone from where I always keep it, and I know that it was stolen by this thieving, lying SOB that my wife hired to do some renovation work in the house. Later she found that he forged a check on her account and speculated that if he would do that he probably stole other things from the house. She decided to not press charges, because she knows his mother, but now I am so angry that this piece of s*&t loser ripped off my scale (which I assume he took cause he wants to make some kind of drug) I feel like putting a bullet in his sorry ass.
Yeah, it could have been worse. Fortunately he was not into large format equipment because he could have made a bundle by ripping off my collection of lenses and cameras.
The only relevance of this to the topic is that I seriously wanted to run a couple of tests and now am here stewing because the equiment I need was stolen.
not being funny but; anything based on the following is to be PUBLIC DOMAIN, FREE FOR ALL USE.
craigclu, in reply to the first question about pH levels, I hope the attched jpeg is of use. It is from 'the American Annual of Photography, 1951(Reinders and Beukers ; Ber. VIII intern. Kongr. Phot.; Dresden, 1931). The only variable in the tests is the pH level of the solutions.
As you can see the inherent contrast of a metol only developer is perfectly predictable and repeatable. It can run from very soft to hotter than lith developer. By adjusting the pH level you can achieve any development from N-4, N, N+4 without changing time, temp, dilution, aggitation or film speed.
By eliminating variables you increase the rate of success, fewer goof-ups in the chain. By keeping the same film speed, you reduce the risk of over-exposure or reciprocal failure. By keeping the same dev. time you give maximum advantage to the shadows. By not diluting the devloper you reduce the risk of blocking the highlights thru exhaustion. By keeping the same developer mix you keep the same base-fog and grain pattern, no suprises. By keeping everything but the pH level the same you can set this up for machine processing, set it and forget it.
A fine starting point is:
75g sodium sulfite
0.4g potassium bromide
1 liter water
start times at HC-110, this is a little hotter
(leave out the bromide with TMX)
If you like the look, have fun working it up. When I get the time I will play with this more. I have tried this formula with Plus-X, FP4, TMX and TMY so far it works well with all and adjusting the pH does make the expected difference.
Good luck with it and always have fun.
The commercial grade of TEA has some diethanolamine and perhaps some mono, which both have somewhat higher pH. The pH of each of these varies quite a bit with concentration. You don't want to mess with MEA. I doubt that you could get it shipped to you anyway. See the Dow Chemical web site for more data than you thought was possible in PDF form.
Originally Posted by sanking
I have found it useful, especially when experimenting, to have stock solutions of phenidone, amidol, pyrogallol, catechol, hydroquinone and ascorbic or erythorbic acid in glycol. Sandy mentioned the effect of ascorbic acid on Pyrocat and relatives, and the same effect can be had in pyrogallol developers, with the same limitations. Too much ascorbic acid will diminish the stain image.
10% solutions in glycol of all but phenidone and amidol can be made with some heating. A little of each of those goes a long way when they are used as the activator in a superadditive combination, so no more than a 1% solution will be required.
Using glycol for the solvent allows trying various alkalis that are not soluble in glycol a la PMK and Pyrocat. If you find that TEA has sufficient pH, which is true for pyrogallol, you can find a solution of your developing agents in TEA that will allow a single stock solution, or just add the TEA to the stock and change your dilution accordingly.
The formula I gave in a previous post on this thread becomes quite active with the addition of a little of the ascorbic acid stock. About 1/10 the amount of the pyro stock should do.
I read my own writing and as often happens found I couldn't understand it. Specifically, the 1% solutions are of phenidone and amidol. The others are 10%.
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Sandy - File the charges - don't let the bastard off with no consequesnces. If you don't, you are giving him your blessing that it is acceptable to you that he rip you off. And then he may come back your the rest of your gear.
Originally Posted by sanking
I second the motion.
Originally Posted by Kirk Keyes
As the ph increases the developing agent-agents activity
Originally Posted by craigclu
increases; shorter developing times.
As the ph increases the gelatin swells and so takes on
more fluid. The silver halids gain in mobility and grain
size increases. Fine grain developers are of low ph.
Surface development is a characteristic of compensating
developers. FX-1, Beutler's, and even Rodinal, all are
examples; high ph very dilute developers. Dan