sanking said:
I am not sure where the idea started that Pyrocat-HD negatives should look thin. Perhaps someone made an analogy with PMK based on something Gordon Hutchins said the The Book of Pyro. I don't believe that I have every suggested this, and if I did it was a mistake.
Pyrocat-HD negatives have a brownish stain that on first glance looks very neutral. In fact, many people on first using Pyrocat-HD complain that there is no stain, probably because their standard of comparison is the very heavy greenish stain produced by PMK. However, the key to properly exposed and developed Pyrocat-HD negatives is that they should look very much like negatives processed in traditional non-staining developers. It is only when you measure the negatives with a densitometer in blue or UV mode that you can appreciate the impact of the stain on actual printing density.
Sandy King
I know where I have seen many references to thin looking negs...the late Barry Thornton stated repeatedly that Dixactol and Exactol negs would look thin to the eye, but would print as if they possessed greater density. He argued that as the silver was less developed than in normally developed negs, in conjunction with the masking effect of the stain, this meant fine grain.
My own experiences were that I struggled to get anything other than thin negs which printed (on VC) with very low contrast with the times suggested by him (I had to use at least grade 3.5-4 for starters). When I increased dev time (probably a good 25%), I got better contrast, better looking prints, but with Dixactol, the grain became shocking with many fims. Exactol Lux was far better in this regard, tho dixactol was great with 5x4 Fuji Acros. I found that effective film speed was surprisingly good (approx 2/3 stop more than Pyrocat HD when normal agitation used for both). I found that where a neg was thin in the shadows, it printed far better than a conventional neg would have, but I needed more development to seperate the mid tones and actually give me some decent highliights. That said, the highlight areas on good negs were still far less dense than conventional negs.
In summary, I have found that flat negs always print flat, whether Thornton devs were used or not. Thos negs of mine that print well still show good seperation in the neg, albeit with slighltly less density than conventional negs. As Pyrocat HD negs are the same colour as those from Exatol/Dixactol, I cannot see there being a real difference. (I have yet to print my pyrocat negs as my darkroom is out of action for now).
Tom