Keith,
In your Feb 9th reply to Terry King you mention testing palladium with the
dichromate developer method. I've only used the double solution ferris
oxolate method for platinum/palladium, but not with the desirable results
for contrast control that you achieve.
I've got a few questions before trying this developing method of
controlling contrast. My queries come from reading Dick Arentz's
description of Phil Davis' method. Dick recommends keeping six bottles of
developer with different amounts of dichromate in each in order to respond
to a variation of negative densities. With the double ferris oxolate
method that I now use, I can create many more than six different mixtures
for contrast control--supposedly giving greater control than Dick's
recommendation. I can tailor a mixture to exactly the density range of a
negative. In spite of this, the double solution method does not give me
the efficient results I want. Since I work with historical negatives, I'm
looking for a procedure whereby I can go easily (directly?) from a reading
of the neg's density range to the right mixture and exposure time. Dick's
book suggests that I can do so, but there's much "slippage", between a
density reading and a mixture and exposure time.
With your dichromate developer method, do you use more than six mixtures
(bottles)? Also, do the bottles have to stay in a dark area? Do the
mixtures of sodium dichromate and potassium oxalate have a limited shelf
life and exhaustion point? Does it give a different look to the prints?
Currently, I'm using Bostick and Sullivan's EDTA clearing. Will this
work, or do you suggest something else? You mention hydrogen peroxide,
which I've used before to push contrast. Can it be used for clearing?
And lastly, I'm wondering, always wondering in using palladium and
platinum at just how toxic the chemicals are: especially in terms of
fumes.
Well now, it seems that my concerns do not involve a few, but many
questions. The thing is, I've not found a publication to provide a more
detailed description of the dichromate developer method.
with thanks,
Ron Silvers