One of the reasons I would have been very reluctant to do a comparison article between PMK and Pyrocat-HD for publication is because my previous comparisons have shown the results to be so similar (in both sharpness and grain) that I don't believe it would be possible to show any differences unless you made huge prints. I have made comparison 20X24 prints from 4X5 negatives using PMK and Pyrocat-HD and there was absolutely no difference in the prints in either grain, sharpness or tonality. I have also made comparison prints from small sections of PMK and Pyrocat-HD at 25X magnification and observed little or no difference. Sometimes the PMK print looks sharper, at other times the Pyrocat-HD print looks sharper. I concluded from this that the small differences in T-dimension with sheet film or the difference in how flat the film is held with roll film cameras is of much greater importance in sharpness than any difference in sharpness in the developers.
The essential thing, however, for this type of comparison of sharpness, is to develop both negatives so that they have exactly the same effective printing density range. With pyro stained negatives there is virtually no way to determine the exact time of development to give the exact density range needed without using either a densitometer or step wedges, and the step wedges are much less expensive and more accurate.
I strongly suspect that if there are is any significant difference in sharpness between the prints he made from PMK and Pyrocat-HD negatives the reason is that he did not match the contrast and most likely the PMK negatives had greater printing contrast. I am certain that Steve believes that he did match the contrast and if he happens to join this conversation will say that he did. But if he really found differences in sharpness so great that they will show in a magazine, especially in View Camera where the reproductions are not all that good, something was really wrong with his testing procedures. I have corresponded with literally hundreds of photographers who have used Pyrocat-HD after first using PMK and if there was a difference in sharpness of as much as Steve describes I am fairly confident they would have immediately seen and recognized it.
BTW, for those interested in the differences in printing with UV processes with PMK and Pyrocat-HD should look at my article on pyro developers at http://unblinkingeye.com/Articles/PCat/pcat.html As far as I know this is the only information either in print or on a web site that accurately describes the differences and the reasons therefor.
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