From: Jeffrey D. Mathias (jeffrey.d.mathias@worldnet.att.net)
Date: 04/25/00-03:21:18 PM Z
Judy Seigel wrote:
> ...
> But here's something not touched on so far -- has anyone tested the light
> fall-off of the metal or quartz halide bulbs? In my experience, without a
> reflector, the cone of *even* light is relatively small. Of course I
> haven't seen these appliances, presumably they're configured for even
> light, but over what area????
An excellent point. It is difficult to get good uniformity on a large
plane with a bulb having a certain size filament or arc and a reflector
system even if additional optics are utilized. Uniform illumination is
a must. One should keep in mind that the systems for printing circuitry
and graphics rarely require the subtle differences in value as with a
photograph. If tubes do the job (spectrum, intensity), it is much
easier to get excellent uniformity over a large flat plane with them.
-- Jeffrey D. Mathias http://home.att.net/~jeffrey.d.mathias/
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