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lungovw
28-Oct-2020, 08:46
I was searching for a high acutance developer and went back to Hypercat, a developer I tried some years ago. Sources are OK about Stock Solution B but for A there are two versions:

In the official page "hypercatacutancedeveloper" I found:
Stock Solution A
ascorbic acid 1g
catechol 10g
propylene glycol 100ml

I prepared it and even by placing a piece of HP5 in daylight, in working solution, it takes several minutes to start darkening while the recommended developing time is from 5 to 7 minutes. At first, I thought that there might be something wrong with my raw chemicals. But looking further, I found a different formula with half content of the ascorbic acid. What is the right content of Ascorbic Acid? Could that be the reason for such low activity in my developer?


This is the one in Digital Truth and also in Focal Darkroom Cookbook

Propylene glycol, 75.0 ml
Ascorbic acid, 0.5 g
Pyrocatechin, 10.0 g
Propylene glycol to make 100.0 ml

Jim Noel
28-Oct-2020, 09:07
i use the original formula. rarely do I use ANY formula from DR Cookbook. Too many inconsistences,

esearing
29-Oct-2020, 04:12
Part B drives your activity, increase partB and/or time. Jay indicates times of 12-15 minutes for 400 speed films but it may depend on the Part B formula you are using. I prefer the stock potassium carbonate (1:100) vs working solution sodium carbonate (5g/liter) for part B.