> I spent last week at a BTZS workshop with Phil Davis who I'm sure
> some of you know or know of. Besides myself, there were 2 other pt/pd
> printers so much conversation related to alternative processes. Phil
> is the person responsible for the sodium dichromate method of
> contrast control described in Dick Arentz's book on pt/pd process. In
> a discussion of UV light sources, Phil said that he had made a bank
> of fluorescent tubes using regular cool white bulbs which were
> comparable in printing time to black light bulbs. This seems almost
> heretical, but considering the cost differential between the 2 types
> of bulbs, I suppose it's worth trying for anyone making a new light
> or replacing old fluorescent tubes.
>
> Keith Schreiber
> Center for Creative Photography
> University of Arizona
> Tucson, Arizona 85721
> 520-621-7968
> 520-621-9444 FAX
> keith@ccp.arizona.edu
>
there are two types of black-light tubes, coated and uncoated. the
coated tubes are more than twice as slow as the uncoated, and cost almost
twice as much. my own bank of florescent tubes is way faster than a bank
of cool whites, i use the uncoateds. See my article "the platinotype" in
the Jan. 94 issue of View Camera magazine.
I would suggest you try my hydrogen peroxide method of contrast
control as outlined in the July 94 issue of the same magazine, as it
offers advantages over all other contrast control methods.