Re: Dichromate dilution and speed

Drum roll........

Okay, my curiosity got the better of me and I've spent the day comparing
saturated to diluted dichromate using a digital negative (everything the
same as the other day except the negative) and I'm prepared to say that
though I've happily printed all kinds of negatives with saturated
dichromate, never noticing any great differences between them (but
understand, I work intuitively, not by measuring, so I may make
intuitive adjustments for the different materials without realizing it)
the behavior of the digital negatives when you start messing around with
concentration is TOTALLY WEIRD. I can't make heads or tails of it.

The weirdest part was that the prints I made with the diluted
concentration were lower in contrast (that's what I said, LOWER
contrast) than the ones made with saturated dichromate. I thought I must
have made a mistake in measuring and got too little pigment or too much
water in the solution, so I dumped it out and re-measured everything,
but I got the same result the second time.

The other thing is that none of the 5 exposures (1x,2x,3x,4x,and 5x the
exposure time of the good print made with saturated dichromate) made a
good print; while there was an image on the paper at the end of each of
the times except for 1x, in no case were the tones or the relationship
between them correct, and their badness didn't seem to have any
meaningful trend in terms of exposure, so there was no way to evaluate
which was the best exposure of the four. If I were to give a wild guess,
I'd guess that around 3x might be about right, but it's just a wild
guess. (I know, it would be better to show this than to tell it, but
that would require walking back out to the studio to see if the prints
are dry, and I'm too tired to move.)

There's no way I would draw any conclusion from this as far as
dichromate dilution and speed except to say that all bets are off when
it comes to digital negatives, and that I'm much more willing now to
believe that if Sam is printing at "about the same" time with the
diluted as with the saturated (I didn't follow all the hedging about how
long is way longer and how long is about the same, so I don't know where
that all came down, but as for me and my house, 5x is WAY longer, and 3x
is way longer, and 2x is still twice as long, for heavens' sake, which
is hardly "about the same" in my book) then the digital negative may
well be the cause.

Katharine
Received on Tue Dec 2 17:12:19 2003