From: Ed Stander (glassact@compuserve.com)
Date: 07/11/02-07:34:02 AM Z
Sandy:
There are two kinds of metal halide bulbs out there. Low voltage (= low
temperature) metal halides are really just mercury lamps. Most low cost
graphic arts lamps (such as the Nuarc) fall into this catagory. If you
raise the temperature on the bulb ( as in the higher end olec and violux
graphic arts lights), you can add other materials - such as iron - and
thereby spread out the spectrum.
I recently looked at the difference between an Olec mercury and Olec
mixed halide lamp, and found that, at least for gum, the mixed halide lamp
gives much faster exposures (2-3x as fast), and somewhat more contrast in
the final product. Cheers, Ed Stander
This archive was generated by hypermail 2.1.5 : 09/19/02-11:11:00 AM Z CST