I use what is called a self-ballasting Mercury Vapour Lamp. This is a MV
lamp that screws into a regular incandescent socket (though a heavy duty one).
It is different from ordinary MV lamps. A regular MV lamp needs a special
fairly expensive fixture with all the appropriate electronics (ballasts).
The self-ballasting MV lamp has all the electronics built into it. They can
be bought from larger lighing supply places. They usually come in the range of
160 - 250 Watts, and cost around $50.00. This is probably the easiest light
source to set up.
Mine works well with gum printing, I use ammonium bichromate as sensitizer and
my exposure times are between 5 - 15 minutes depending on the negative. I
contact print 4x5 so I can get the lamp quite close to the printing frame.
The other popular method is the use full-spectrum or UV flourescent tubes.
You must build a bank of them to provide even lighting. You should be
able to build one fairly simply, by buying a set of small strip lamps and
mount them on a piece of plywood and put sides on the plywood to raise
the lamps off the surface. The printing frame can be slipped under the lamps.
>I've just started doing monochrome gum prints recently and have been exposing
>the paper in sunlight with good results. However, I'd like to have a more
>reliable light source. I've called numerous specialty lighting and bulb shops
>in my area (Atlanta) looking for a 275 watt sunlamp, but no one sells them
>anymore - most have said that I would need a doctor's prescription to buy one.
>So, are there any alternatives to a sunlamp, or is there some place I could
>mail order one without a prescription?
>
> Thanks,
> Scott
>
>--
>Scott L. Robertson
>Graphics, Visualization and Usability Lab
>Georgia Institute of Technology, Atlanta Georgia, 30332
>slr@cc.gatech.edu
________________________________________________________________________
Gord Holtslander Department of Biology
HOLTSLANDER@SKYFOX.USASK.CA University of Saskatchewan
Saskatoon, Saskatchewan
Tel (306)966-4433 S7N 0W0
Fax (306)966-4462 Canada
________________________________________________________________________