RE: my first van dyke!!

As I mentioned in my first post about using the Mylar, I use "a fairly
collimated source." It's a mercury vapor source mounted two feet above
the vacuum frame. No doubt, the combination of vacuum contact along with
  the semi point-source light minimizes any image softening from the
0.002" Mylar sheet. Still, I've seen students use it with fluorescent
sources with no problem. Guess the best advice is to try it and see if
it works for your conditions and materials.

I actually talk about image softening as related to light source and dot
structure on page 172 of the second edition of "Making Digital
Negatives." There's a nice illustration that helps explain the effect
too. ;^)

Hope this helps!

Dan

Breukel, C. (HKG) wrote on 10/11/05, 9:22 AM:

> Do not know about other materials, but I tried Saran wrap (have to dig
> up the width, pretty thin I would say), but on smooth surface paper
> like Simili Japon I always saw a decrease of sharpness, enough to not
> use it again, and run the risk of damage my negative (none so far,
> only a stepwedge)
>
> best,
>
> Cor

-- 
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