VC question - Characteristic curves

[Francesco Ricci <ricci@itc.it>]

Hi,

I've a question for you. I normally print VC paper with my Durst 670
colorhead. I do not mix yellow and magenta. When I need more contrast I
increase magenta and when I want to reduce contrast I decrease magenta till
0, then I increase yellow. I compensate and make a lot of test. 

It works, but, assume that 50 Magenta yelds 2 and 1/2 (it doesn't matter
here if this is the real number), and that you can obtain the same degree of
contrast with 45M and 20Y, do the two characteristic curves have the same
shape? I've always assumed that combining Yellow and Magenta, as suggested
for example by Ilford, is meant to avoid time compensation, but I wonder if
the paper reacts at the same way, for example in the highlights or in the
shadows.

Any hint, maybe someone have alredy done a test with a step tablet??
cheers

- -francesco

BTW I've recently developed some rolls of TMY400 with Xtol. With diluition
1+1 and 13 min (5 sec agit. each min) at 20deg I must print with 50-100 of
Magenta. The speed was set to 250ASA. Grain is obviously less than Rodinal,
which is my preferred dev., and sharpness is not bad.


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Francesco Ricci, IRST, Loc. Pante' di Povo, 38050 Trento, Italy Tel:
++39-461-314334, Fax: ++39-461-302040, email: ricci@irst.itc.it WWW
http://mnemosyne.itc.it:1024/ricci
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