Improved pyro-ascorbic developer

[Tom Hoskinson]

Further to my post above, I have looked around and found that TEA on its own has not a high enough pH for pyrocatechol. How would it go if I made Pyro-510 with pyrocatechol instead of pyrogllol, and then used, say, 1 part/100 of 750g/mL potassium carbonate as part_B. Are TEA and carbonate ok together?

Yes, based on my testing, TEA and carbonate (either sodium or potassium) are ok together. I usually add the carbonate as a Part B stock solution to the working developer.

On occasion, I have also added a few grams of monohydrated sodium carbonate to the working developer. Either method works fine.

 

[John Z.]

I was wondering if you could substitute Sodium Carbonate Monohydrate for Sodium Hydroxide. I find Hydroxide a little tricky to work with. If you were to use Metol for Phenidone, would you use 2.5 gr here, which would be a 10:1 ratio suggested before?

I would be curious if anyone has tried the new formulas and my preferred films, Efke 100 and TMY 400, printing on AZO paper? It would be good to hear about some results before considering changing from my current favorite developer, PCAT in semi-stand development. Thanks,

John Zdral

 

[john_s]

I was wondering if you could substitute Sodium Carbonate Monohydrate for Sodium Hydroxide.
John Zdral

Thanks Jay for the hypercat formula using pyrocatechol. I'm also curious about using carbonate. I have 750g/L potassium carbonate made up to use with pyrocat-HD. Could I use that instead of the hydroxidefor part_B? And in the same proportions? Might it reduce grain a bit?

Also, I use pyrocat-HD without the bromide and it gives a shade more speed. I'm not worried about a little fog. Could I leave the benzotriazole out of the hypercat without getting significant fog?

 

[john_s]

.......I would remind you that developer exhaustion is an important part of the development process, and can have a dramatic effect on image sharpness, film speed and curve shape.....
Jay

Jay. thanks very much for your prompt reply. My wild guess/assumption about carbonate vs hydroxide was based on comments that I've read about hydroxide giving additional grain with pyrocat-HD.

About developer exhaustion: I have always tended to use a generous amount of developer to be on the safe side, and to develop with only enough air in the tank to allow a reasonable amount of agitation when I do inversions. This naturally leads to less exhaustion and/or oxidation. Is developing with hypercat more critical if it relies on developer exhaustion? Should the amount of developer be deliberately limited to cause exhastion?

One final question: comparing pyro-510 and hypercat: I was intrigued by a post here recently that said that pyro-510 gave very good film speed with FP4+. I usually use 400 speed film in 120 with pyrocat-HD, rated at a bit under 400. If I could get good speed out of fp4+, I would probably get finer grain than with my 400 film. Which of the two developers would get me the highest speed?