Re: Blue gels and Pt contrast

William Laven (wmlaven@platinotype.com)
Sat, 21 Feb 1998 12:16:43 -0800 (PST)

But while both of them
>drop off drastically between 365nm and 405nm, Users of Super actinic
>tubes are making prints, and their output peaks around 420nm. This from
>an area indicated by Ware research where very little should be
>happening.
>
> Are all users of super actinic tubes using traditional ferric or do
>any use the ammonia based ferric?

Eric's letter was filled with interesting points and rhetorical questions.
I'll just address one of them which pops up on the list every few months,
ie in this corner, the Black Light weighing in at 350 nanometers and in the
other corner, Super Actinic weighing in at 420 nanomenters. On several
occasions I have tested Black Light vs. Super Actinic and the results are
always that the Super Actinic is faster for both Palladium and
Platinum/Palladium mixes. I use traditional ferric oxalate; the tests have
happened with some FeOx that was months old and some that was freshly
mixed. Whatever might be said about the superiority of a Black Light, it
just hasn't panned out that way with Pt and Pd.

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WILLIAM LAVEN PHOTOGRAPHY

Offering Platinum/Palladium printing services and workshops and tutorials
in Pt/Pd printing and other areas of photography (Zone System, etc.)

1931 23rd Street, San Francisco, CA, 94107
415-647-9432 (voice) 415-647-9438 (fax)
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www.platinotype.com

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