Re: uv with metal halide vs florescent bulbs

On Sun, 14 Mar 2004, Sandy King wrote:

> I am about 99.99% sure that a remarkable difference in Dmax is due to
> reasons other than the light source. I have never printed Ziatypes
> but in my work with carbon, Pt/Pd, Palladium and Kallitype my bank of
> BLB tubes prints with almost the same contrast as my NuArc 261K
> platemaker with a metal halide tube, and in fact the tube bank is
> slightly faster than the platemaker. And I have printed with
> Pictorico OHP with both types of lights.

well, here's a funny one -- an article by Peter Brickell in (the forever)
upcoming Post-Factory shows a dramatic difference by light bulbs in color
intensity (also scale) in gum printing... no halide involved, but carbon
arc, also daylight fluorescents. I did some stuff with cyano & VDB with
those variables long ago.... the differences weren't dramatic, and seemed
offset by differences in speed, but were there.

Also, while you're figuring variables, check the glass. The two different
light sources may have different glass over the sandwich. I found that
the vaunted Starfire glass on my Nu Arc (after breaking the vacuum glass)
was so contrasty I couldn't use it... It's still around here somewhere.

J.

.
Received on Sun Mar 14 16:51:31 2004