From: Michael Healy (mjhealy@kcnet.com)
Date: 10/30/02-09:56:35 AM Z
I've been trying my hand at cyanotypes, as a prelude to some albumen paper
that I am making for use in the next month or so. I am having trouble
figuring out a couple things.
(1) use of the Stouffer tab and (2) appropriate neg density. BTW, I am not
using a densitometer, and I am using the sun. I do not and will not have
access either to a densitometer or to a UV lamp for the foreseeable future.
(Fortunately I am getting my sun from Arizona not Minnesota.)
(1) Stouffer tab -- I am following John Barnier's instructions. I understand
that the tab lets me figure out a minimum exposure for dmax for a specific
paper/neg combo (sun, too) at step #2. What I find, though, is that most --
MOST -- of my densities fail to print out at this exposure. No, more
specifically, my neg is comprised OVERWHELMINGLY of densities beyond step
#2. Of course, increasing my exposures merely produces muddier prints.
Obviously by a strategy of overprinting, I add the neg areas equivalent to
step #3, #4, etc., to dmax, so I have "more" shadow area; but even with this
overprinting, so much of the neg remains completely beyond this range. If I
print for good shadows, then everything from midrange up to highlights is
blank. If I print for midranges, then the cost is that some of the lower
midranges go to dmax as well.
First of all, am I approaching the use of this tab effectively? Are there
other things I should be trying to "read" than what I'm deducing?
(2) neg density: I understand that for 19th c. processes, we need to
"overexpose" in relation to what we normally expect for Ilford multigrade.
And also that we want to develop at least normal, if not plus a stop. The
idea of overexposing now makes total sense to me in light of what the step
tab is disclosing. Overexposing the neg development would make denser
shadows, thus requiring longer print time. The longer time would let the
midrange densities print out after all, but w/o causing so many lower
densities to reach dmax prematurely.
What I don't understand is how longer neg DEVELOPMENT time will to help. In
platinum, yes, since it is self-masking. (Is albumen self-masking? It should
be, since it's the same chemistry as POP, but I can't remember whether I've
seen anything explicitly saying so.) But w/ cyanotype, this idea doesn't
make sense to me at all. Making the higher densities even denser will just
mean putting them that much farther from the lower densities that I just
made denser. IE, an overall denser neg will demand longer exposure for
shadows, but this longer time won't produce better registration in the
midrange densities. Sounds like tail-chasing.
It seems to me that the only thing I want to do -- for cyanotypes -- is to
overexpose, but NOT overdevelop. IE, shouldn't I want to constrict my neg
density range for cyanotypes, rather than expand it?
Mike Healy
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