U of S | Mailing List Archive | alt-photo-process-l | Re: photopolymer

Re: photopolymer


What is the resolution in DPI of the imagesetter they are making these finer screens with?

Best Wishes,
Mark Nelson

Precision Digital Negatives - The System
PDNPrint Forum at Yahoo Groups

In a message dated 5/5/07 4:25:36 PM, jon@terabear.com writes:

Hi Keith,

I tried working with the Welden screen and tested it for several months
in conjunction with various finer line and stochastic screens, so I'm
quite familiar with it.  It works fine, of course, as I'm sure your work
and Susan's latest prints will attest.   The basic difference between
the finer one I use and Dan's/Elizabeth's is that the pattern with
theirs is visible to the naked eye. Mine just looks like a dark grey
translucent screen. I'd guestimate theirs to be somewhere on the order
of 150-200 dpi compared to the 1800-2540 dpi screens I've been using. 
The inkjet positive of course is the defining factor, and so having
aquatint dots larger than the image dots is the main reason why I moved
away from it.  Once an area of the plate has been burned in with a
'white dot', no further definition of tone is possible in that area,
thus, more contrast.  Finer dots mean contact is even more of a critical
factor, however.  The standard screen is more forgiving in that regard.

I spoke with the graphics firm I've been working with in Denver on
Friday.  The finer stochastic screens I've asked them to make work well,
but there was still this issue of a washout pattern (which doesn't seem
to read on the plate) which I'm hoping gets addressed when they do the
next PM/chemistry change on their SciTex imagesetter (for aesthetic
reasons if nothing else).  After the PM (regardless of the aesthetics),
I'll send you, Susan and Chris samples to play with and will post
contact info on the company.  I've been told to get back in touch with
them in 2-3 weeks regarding the PM.  Their screens are working well, as
I said, but are not as fine looking under the lupe as the ones I used to
get from Peter Ellzey Copy Graphics in Santa Fe.  Not sure it matters
that much since my tests show there's little difference to the human eye
between super-fine (2540 dpi) and fine (1800 dpi) once the stuff has
been translated to poly plate and back to paper anyway -- curves adjust
tone as needed in both cases and create very similar results in the
end.  I've recently found and been in touch with the elusive Mr. Peter
Ellzey, formerly of Copy Graphics, who has some ideas about how to
reproduce the screens he used to make for me with their Agfa
imagesetter.  There was some confusion both with him and Copy Graphics
regarding the use of Icefields software to create the 1800 dpi screens
for me.  I kept all the tests we tried and looked at them yesterday. 
Icefields is definitely NOT what we were using, assuming they were
labeled correctly.  Icefields screens were more coarse and with a
pattern more visible to the naked eye.  Peter has kindly agreed to talk
with Copy Graphics and try some stuff next week for me.  Very happy to
hear he's doing well, teaching and working in film production, but still
with an avid interest in this stuff.  I'll keep you posted on these
developments as well.


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