I have been learning a lot from my 361t - Things I would not have otherwise known. Making sure that both ortho and uv calibrations are correct, I have been eveluating my pyrocat negs and my xtol negs. For the same ortho density areas, UV density is often twice the density. I have been limiting my experiments to FB Grade 2 paper. J&C Classic for now (which seems to have a nearly identical tonal scale as Forte - which is now harder to get.) My enlarger uses a Condenser head with a standard 150W light bulb. (Omega 6 pro series.) I have used development times (for pcat) that I have tweeked over the years to print a tonal scale for a EV range of approximately 7 for TRI-X and 5 for FP4. My paper can print a density range of approximatly 1.35.
The unanswered questions are: How significant is the UV share of total light passing through my negatives? What is the Grade 2 paper response to the UV component?
I know that UV has a significant impact intuitively. Visually thinner stained negs print with the same contrast as denser non-stained negs. It stands to reason that for equivalant ortho densities - the contrast will be significantly greater for the stained negatives - as I have seen.
AZO and other alt processes use UV and contrastier negatives - 1.7 or more. This makes pyro clearly better for those process and these negs should probably be evaluated in the UV channel almost exclusively. But what is the benefit for Grade 2 FB paper? If my light source contains UV as part of its emission (guess maybe 35%) and an XTOL negative is the same density at UV and Ortho - The image is simple and the process of matching the scene contrast range to a negative range that fits the paper range is straight forward. But if the highlight densities of a stained negative block 20% more total light - that adds a complexity to the process.
There are many good reasons to use staining developers on enlarging negatives - I wonder if a blocking UV source filter would simplify and improve or if it would increase the grainieness because the stain has a smoothing effect on the image. One of the differences between Pyrocat and PMK has been the overall stain (PMK has overall stain and pcat doesn't). Such an overall stain might equalize the UV and Ortho densities giving it an advantage (simplification) for enlarging. (Much less desirabel for alt processes.) The p'cat negs are much finer grain making it better for roll film as well. I am not sure what the conclusion is to all this - so I am looking for the comments from the brain trust here for insight - or correction - If I simply got it wrong - Thanks