"Grow" lights are not the most efficient for exposing alt photo stuff.
If you check with a local lighting supply house they can get you bulbs that
provide max output in the near UV.
If your local folks can't help you then try the manufacturers and/or
Bulbman, referred to in an earlier thread on the list.
-----Original Message-----
From: terryroth@earthlink.net [mailto:terryroth@earthlink.net]
Sent: Thursday, May 14, 1998 1:07 PM
To: Phaedrus
Cc: Alt-Photo
Subject: Re: lights
Phaedrus wrote:
>
> I've been using a fluorescent "grow" lamp for exposing gums, but am
> not really pleased with the contrast or exposure time compared to real
> sunlight. Having been in the clouds this past few days has prompted me to
> find another source. Can anyone offer suggestions, barring expensive
> printshop units?
>
> Peter Howey
> Kirtland College
*********************************************8
Peter, as I experiment with Puget sound sunlight (actually rain) for
exposing kallitypes, I have found that overcast sky still makes an
image---it takes longer, of course, but the image seems to have about a
half-paper grade more contrast. If the short-length UV (200-300nm) is
selectively absorbed by the clouds, but longer-wave (in the 350-500 nm
range, where ferric compounds are most 'absorptive'), this would explain
why the image is still formed, though the intensity of the light is
diminished. I have no idea why the contrast is different, perhaps one
of the expers on the list will explain.
--Ter