Pyrocat Inflection

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From: Sandy King (sanking@clemson.edu)
Date: 11/26/01-10:43:59 PM Z


Clay,

Yes, I changed to the 2:2:100 dilution over a year ago because with
some films, notably HP5+, I was getting more stain density, including
some elevated b+f, than I wanted and I reasoned that increasing the
amount of A solution, which contains the preservative, would cut back
on the stain. However, to be perfectly honest, my subsequent tests
indicate that there is little difference between the 1:2:100 and
2:2:100 dilution and the problem seems to be with the film so if you
like the results with 1:2:100 don't change. I also tried a 2:4:100
dilution to try to get even higher contrast for very flat lighting
conditions but this dilution was virtually the same as 1:2:100 and
2:2:100.

I am curious about the inflection in your curve. Do you have a
picture of the curve you can send me as a file. I see a slight hump
in my own curves, with the hump beginning at about 0.9 and dropping
back down at about 1.5. This varies a bit with time of development
but is most notable at development times of 12-15 minutes.

>Sandy:
>
>In noticed in another post that you're using Pyrocat HD at 2:2:100 for alt
>process negs. Is that recommended now? I've been getting the extra contrast
>using 1:2:100, which may explain the inflection in my H&D curve. Any
>thoughts?
>
>Clay
>----------
>
>>I use rotary processing (tubes and drums) for all of my negative
>>processing. With staining developers I use a water stop-bath and
>>alkaline fixer and get a very low B+F with both ABC+ and Pyrocat-HD.
>>
>>
>>Sandy King
>>--
>>

-- 


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