Re: Flourescent tubes (350 nm range)

NADO000 (LNADEAU@unb.ca)
Tue, 16 Aug 94 20:47:33 -3

>
>I am building an exposure unit for alternative processes and was
>wondering if there is anyone out there who has had experience with
>fluorescent tubes made by Voltarc or Phillips (is anybody out there -
>it's been awfully quite lately?). Specifically I am interested in any
>tubes that might reduce my exposure times from that obtained by using
>a standard "BL" tube. The reason I raise this question is because I
>understand that ICP (International Center of Photography - NYC) has
>installed Voltarcs in their new darkrooms and they are said to reduce
>exposure times; I have yet to speak with anyone who has done a direct
^^^^^^^^^^^^^^^^^^

For what process? The amount of time required to properly expose a
light sensitive emulsion is not dependant on the *power* (in Watts) of
the light source, as much as the particular nature (wavelength) of the
source and the light sensitive emulsion.

With my Berkey metal halide platemaker, exposure times run around 4
minutes for palladium, 10 to 12 minutes with platinum, and 20 seconds
to 2 minutes with Fresson printing and carbon transfer.

Luis Nadeau

>comparison. The Phillips bulbs, I believe Phillips calls them
>"Actinics" draw 40 W. as opposed to the usual 20 W. (they require a
>special ballast); again I have not spoken to anyone who has actual
>used them.
>
>Anybody out there?
>
>greg schmitz
>gws1@columbia.edu
>
>
>PS: cross-posted to Usenet group rec.darkroom