Believe it.(posted 8842 days ago)After reading about pyro for years I gave it a try with HP5+, compared with D-76H 1:1 and 1:3, 35mm, using the same camera, lens etc, shooting both test strips and my standard test subject, a white stucco house across the street.
First of all, it "worked" fine with plenty of stain but not much overall stain. Although it's difficult to read a pyro neg with a densitometer, I followed Phil Davis' suggestion that the printing density on VC paper would be about halfway between the white-light reading and the blue-filter reading.
In printing, the stain did its thing; I got lots of highlight compression on VC paper but not so much that the light tones blocked. There was sufficient tonal differentation.
I can see how it'd be wonderful for alt printing in which a high- (printing) contrast neg is needed.
However, I found less apparent sharpness than with HP5+ in D-76H 1:1 or 1:3, and about the same or very slightly more apparent graininesss than 1:3. The differences are rather subtle and probably wouldn't be visible at all with bigger negs.
Why test with 35mm? Because it present the worst case.
I wouldn't hesitate to use pyro with large format if I want that sort of highlight compression, which can at times be very useful. But I get a much straighter curve shape with D-76H 1:3 with a reduced development time for those "heroic measures" occasions.
Certainly there's a period of "getting to know" new materials or procedures, but for me the new material or procedure must show something worthwhile; pyro shows a very easy way to handle those very-high-contrast scenes, especially those with lots of highlight contrast, but at the cost of reduced apparent sharpness and slightly more grain.
So pyro is going into my bag of tricks, but not as a standard developer.
Your mileage may vary, of course.