FotoDave@aol.com
Date: 06/26/00-09:33:47 AM Z
Brian,
If you want to be very precise, you should measure the density or zone IV and
zone VI (or some people use zone III and zone VII but it's just a preference)
AND zone I and zone IX.
If you are doing standard silver gelatin, or if are using large format
negatives and process them specifically for your process, AND the situation
is like you described (that is, it has the deep black and bright white), then
measuring the texture range (zone IV and VI) alone should be sufficient
because the zone I and zone IX is more or less *assumed* to fall in the right
place.
But if you are doing negative, interpositive, and final negative again, you
go through the toe and shoulder and toe and shoulder and toe and shoulder of
the film, so although you might get the texture range exactly right, but the
contrast of the deep shadow or bright highlight might not be right. Take
shadow, for example, if the contrast from zone I to zone III is too high, you
will have some part of the shadows going into featureless black. If the
contrast is too low, you will have separation but won't have the deep Dmax
that you like. The other way is similar, you might have featureless white (if
too contrasty) or grayish highlight (if too flat).
Once you are consciously aware of this, there are different ways of
controlling the tones you want. For example, zone VII can be controlled by
development, zone IX by dilution and compensation, zone III by exposure, zone
I by flashing. However, to control all 4 tones *exactly* the way you want it
is difficult, but if you go through the positive - negative stage, it is not
too bad.
If you use lith film developed to low contrast (have to use low-contrast
developer, not just diluted Dektol) for you intermediate stages, since the
lith film have a pronounced toe and shoulder, you can control many things
separately. For example, let's say we are doing the interpositive (highlight
is the low density now), you can place (through exposure and flashing if
needed) zone IX and zone VII right, you might find zone III not right, by
altering development, you can change zone III w/o affecting much on the
highlight. Once zone IX, VII, and III are right, you might find zone I not
right. This is difficult to control, but you can do it in the final negative
stage (that is, working in reverse, you control zone I and III through
exposure and/or flashing, and control zone VII through development. Zone IX
will fall right if you have controlled it right in the interpositive stage).
Last November I announced my SDC (direct-carbon) process, and from that time
till now I am actually working a lot in calibrating the negative instead of
the process itself (the process itself is actually quite stable), and I do
use everything that I said above. I just finished the calibration and will
prepare a small portfolio of prints using the process (after I printed all
the requested samples and a few prints-of-the-month). I will let the list
know when it is done.
Dave Soemarko
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***** See Soemarko's Direct Carbon (SDC) prints at
***** http://hometown.aol.com/fotodave/SDC/
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