Is there a reason that in the massive amount of info that Sandy has produced and generously presented to us, there is no graph for HP5+ at 100+1+1 dilution? Obviously long development times might be an issue for some people, but an extra 5min would not bother me.
Yes, there is a reason. In fact two reasons.
First, I am primarily an alternative printer and for my own work use almost exclusively the 2:2:100 dilution. For the broader benefit of Pyrocat-HD users I have done some testing with the 1:1:100 dilution but not nearly so much as with the 2:2:100 dilution.
Second, every single one of the CI charts provided represents at least 3-4 hours of time. This includes:
1. Exposing five sheets of film for exactly the same time to a 21-point step wedge.
2. Developing each of the sheets of film for a different time (calculated from about 0.5X normal to 2X normal, assuring temperature control of +/- 0.5 degrees for all stages of processing.
3. Reading the densities of each of the five sheets at all 21 points of the step wedge. (5X21 readings = 105 total) Different readings are required for silver papers/AZO (Blue reading) and alternative processes (UV reading).
4. Entering the data into WinPlotter. (5X21 entries = 105 total)
5. Analysis of the curves and transfer of the graphics from WinPlotter to PhotoShop to Word.
As you can see, providing useful testing information takes a lot of time. If there are other WinPlotter users who would be interested in running tests and sharing the data for films (and/or dilution) that are not covered in the article I would be very interested in including CI charts of these tests, with credits.
Thanks. I have been aware of Pyrocat-HD for a year or two and assumed that it would be less suitable for my purposes, ordinary silver printing on VC and occasionally on graded papers, using 120 and some 35mm. I use PMK generally and have been happy with it, except that I've experienced some variations when I've mixed up a new batch (despite being quite careful).
First of all, film shot for enlarging is never developed in Pyrocat at a 2-2-100 dilution. The 2-2-100 dilution is for negatives designed for alternative process or Azo. That explains why your negatives are contrasty. If you take the 2-2-100 time on the blue channel reading of HP5 and use the same amount of time but cut the dilution to 1-1-100 you should be fairly close.
It was Sandy's recent article that prompted me to try his developer. Obviously one needs to be prepared to experiment when starting out on a new and rather different developer. What surprised me, and I still don't understand it, is that I chose the time for gamma=0.5 which I thought would have given me the level of contrast I was looking for.
Anyway, I'll follow your advice and report back.
What surprised me, and I still don't understand it, is that I chose the time for gamma=0.5 which I thought would have given me the level of contrast I was looking for.
Two quick notes.
First, I looked at my data again for the 2:2:100 dilution of Pyrocat-HD with HP5+ and it agrees with the chart in the artilce. For a CI of 0.50 my tests indicate that you need to develop HP5+ for about 6:30 minutes at 72F. This is based on a densitometer reading with the Blue channel and applies to silver gelatin printing.
Second, please note that at another spot in the article I indicated that persons experienced with PMK could correlate that information to the 1:1:100 dilution of Pyrocat-HD by multiplying the PMK time by 0.70. From that I calculate that for normal SBR scenes a time of about 9:00 minutes at 72 F would be about right for HP5+ when developed in Pyrocat -HD 1:1:100.
Hope this information is useful to you.
Thanks Sandy. It is helpful. It won't take long to home in on the right time. My choice of .5 was just guesswork, since i don't do such measurements. My PMK times are shorter than normal for some unknown reason (not the water quality). I'm hoping that Pyrocat-HD will be more consistent for me from batch to batch. I currently have three lots of PMK all different, all carefully made at different times using chemicals from the same supplier.