Quote Originally Posted by jdef

Sandy, thanks for clearing up my Ph confusion. I've never used Pyrocat or PMK, so I have no basis for comparison with those developers. As for diluted TEA developers, I think Patrick has already addressed that and suggested that the addition of sulfite would equalize those differences.

I missed what Pat said about adding sulfite to equalize the differences in diluted TEA formulas. How much and at what dilutions? I would personally consider this a major complication to have to add extra sulfite to a pyro staining developer because the sulfite will almost certainly affect the intensity of the stain, and printing contrast of the negative.

In a broader sense I have looked rather carefully at the advantages and disadvantages of the one solution pyro formulas based on TEA as compared to two solution formulas in which the A solution is stored in propylene glycol, and determined that for my own purposes, which involves developing film both for the relatively low CI needed for silver papers and the higher CI needed for alternative work, the two part formula offers quite a bit more flexibility. Using TEA as the accelerator, with pyro or pyrocatechin in combination with either metol or phenidione, has resulted in unacceptablly long development time to reach the needed contrast, and quite a bit more B+F than I get with Pyrocat-HD.

Sandy