Re: Dichromate dilution and speed

On Wed, 3 Dec 2003, Christina Z. Anderson wrote:
> It seems, so far, you have at least several people the low strength
> works for (Sam, Suzanne, myself, not to mention Sam's former students) and
> at least several people it doesn't (Keith, Katharine, and Judy, Kerik, Clay
> maybe?).

To characterize my position as saying that low concentration doesn't
work is to distort it beyond recognition. I went to some lengths to make
clear that I think this is probably a good way to go, that with a
properly calibrated negative and with some understanding and skill based
on experience with the method, I have no reason to doubt that a person
could get good results this way. I went on to say that I came from a
different approach, not a better approach just a different approach, and
that I was so comfortable with my approach and with my ability to
effect every contrast range with it, I had no motivation to change, but
that I thought beginners would do well to start with a low dilution and
work up if they want less contrast for some reason. I said all that very
clearly, I think. How it went from that to the above is a total mystery
to me.

Here's the URL for what I said, in case anyone wants to check it against
how I'm characterizing it here:

http://duke.usask.ca/~holtsg/photo/current/0550.htm

I'll restate my findings here:

1. I found that with a contone negative, there was a clear (possibly
straight-line) increase in speed with dilution of concentration. The
lower concentration printed with longer printing speeds and higher
contrast, which was what my question was, so I can't think of any sense
in which my results can be interpreted as "it didn't work."

2. I didn't like the contrast I got with the diluted concentration, but
I also said that I was sure that by adjusting the concentration (and
although I didn't say that at the time, the negative as well) one could
get results one liked. but to say that I didn't like the low contrast,
is NOT the same as saying that for me the low concentration didn't
work..

3. I found that with a digital negative, it was impossible on the basis
of one test to discern any clear relationship between speed and
dilution. But again, I said that part of the problem was probably that
my negative was made for printing a fairly contrasty negative with
saturated dichromate; with a differently calibrated negative one might
get very different results.

To sum up: the only question I was addressing in either test was the
question of the relationship between dichromate concentration and speed.
What I concluded was that for contone negatives there is a discernable
relationship but that for digital negatives I could not determine what
the relationship is, if any. I said Sam could probably do a better
comparison using his own method and negatives. I don't care whether he
does or not; I've satisfied my curiosity on the issues that interested
me.
Katharine Thayer
Received on Thu Dec 4 12:53:39 2003