From: Sandy King (sanking@clemson.edu)
Date: 05/20/03-10:19:23 AM Z
Linas,
Thanks for the report of your good results.
I do have a chart that is more specific regarding contrast control.
It was posted here on the list, and a modified version was published
in the last issue of Post-Factory Photography. For some reason I did
not include it in the article on Unblinking Eye but given the fact
that there have been some questions about contrast control I may ask
Ed to add the chart with a sentence or two of explanation.
DR of negative 4% PD added step-wedge stops
2.25+ 1ml PD per liter 17
2.15 2ml PD per liter 15
1.85 4ml PD per liter 13
1.65 8ml PD per liter 11
1.55 16ml PD per liter 10
1.35 32ml PD per liter 8
The chart above is slightly different from both the one published in
PFP and from the one I posted earlier to this list. The difference
is due to the fact that as ferric oxalate solution ages it gives more
fog, and you must add more potassium dichromate. That is why I
suggest in the article that you mix the the ferric oxalate solution
in small quantities. The above amounts of added potassium dichromate
are what I am currently using with a fairly fresh ferric oxalate
solution, mixed about two weeks ago.
It is also possible to renew the ferric oxalate by adding hydrogen
peroxide, and somebody else might want to comment on that. I find it
just as convenient to simply increase the amount of dichromate in the
sensitizer.
Sandy
>Sandy,
> I tried your Kallitype procedure again last night. This time I
>stuck to your procedure exactly. I’Äôm very impressed with the
>result. I need to use a bit less dichromate for the next go around
>with this negative, but still a excellent print, which looks
>remarkably like my normal Pd/Pt prints (I toned with Pd). I used 10
>ml of 2% potassium dichromate in 400 ml of 20% sodium citrate.
>I’Äôll do a step wedge tests at various dichromate concentrations.
>Do you have some more detailed data you can share regarding your
>preferred dichromate amounts vs. negative DR’Äôs. I noticed that the
>suggested dichromate amounts vary somewhat from the early
>instructions I have and your current suggestions in the
>unblinkingeye article.
>
>Not using my normal very aggressive clearing protocol makes a big
>difference with your Kallitype. This morning I showed my wife this
>print and an earlier Pd/Pt from the same neg (without telling which
>is which) and she preferred the Kalli! I’Äôll do some more testing
>and try an 8x20 neg soon. You may be saving me a considerable amount
>of money with this beautiful and economical process.
>
>Linas
>
>
>Linas Kudzma
>lkudzma@earthlink.net
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