Originally Posted by Josef Guay
Can I assume that your Pyrocat-HD/PMK comparison was on VC paper? If so your findings are opposite of what Steve Simmons reported in his article in the current issue of View Camera. In my own tests I have found that both developers give results that are virtually identical in terms of grain and sharpeness, but most of my comparisons are made based on printing on AZO, other graded silver papers and with alternative processes, not VC.
I agree with you that the dye mask produced by Pyrocat-HD is less efficient than that produced by PMK with VC papers. But with graded papers the Pyrocat grain mask is more effective than that of PMK. And for alternative printing the grain mask of Pyrocat-HD is much, much more effective. And for scanning the Pyrocat-HD grain mask appears to be at least as effective as that of PMK because it gives very clean, almost grain free scans.
Your comments about a possible difference in the reaction of Ilford and Forte papers to the color of the stain of different pyro formulas are very interesting. Maybe others will just in and comment on this. I would like to be helpful but am not working any more with VC papers and projection printing and don't have anything useful to add. Well, I could theorize but results from actual tests or prints are always more interesting.
As for the TEA, no, in my opinion it does not provide any benefits over carbonate or metaborate accelerators other than the convenience of single solution and stability. The key to a good developer is to have a good balance of reducer(s), accelerator, and restrainer if needed. The formulas that I have prepared with TEA work at a pH of about 9.3, slightly lower than the pH of 9.6 of PMK, and quite a bit lower than the 10.9 of Pyrocat-HD. According to some theory the lower pH should give finer grain but I did not find that to be the case in recent tests I did with a pyrogallo/metol developer in TEA.
In fact, there are some real problems with the Pyro/TEA formulas if you use them at other than the standard dilution because this will result in very large changes in pH and in the activity of the working solution.
Last edited by sanking; 09-03-2004 at 05:53 PM. Click to view previous post history.