[LargeFormat] Ultrabiglargeformatcamera

[tripspud]

Hi Richard,

     One of my client's back in the '70s was a job
for a printing house or something.  Anyway,
I got a tour of a very large printing house
with five floors heavy machinery,
now 99% obsolete.  I wish I'd
saved a catalog of pro gear
I had back than.

Cheers,

Rich Lahrson
Berkeley, California
tripspud@transbay.net

Richard Knoppow wrote:

> ----- Original Message -----
> From: "Jim Brick" <jbrick@elesys.net>
> To: <largeformat@f32.net>
> Sent: Wednesday, March 05, 2003 3:13 PM
> Subject: Re: [LargeFormat] Ultrabiglargeformatcamera
>
> > The camera is a process camera, used by the semiconductor
> and printing
> > industries for decades. I ran one of these in the early
> 60's. As process
> > cameras go, this one is not particularly large. Those used
> for making
> > semiconductor masks make this one look like a toy.
> >
> > Process cameras for the printing industry used arc lamps
> (later pulsed
> > xenon lamps) and were used to make line and halftone
> negatives.
> >
> > Process cameras for the semiconductor industry used a very
> sharp cutoff
> > green light and lenses that were made to be exceedingly
> sharp only at that
> > one wavelength. These cameras were made to be able to
> reduce man made
> > semiconductor layer tape-ups (very large) down to
> microscopic size for
> > masks from which to manufacture integrated circuits.
> >
> > The big process cameras were focused by the numbers. Not a
> loupe and ground
> > glass. A crank on the back to dial-in the number for the
> percentage reduction.
> >
> > Jim
> >
> >
>   Note the sprint shock mounts on the bed!
>   The whole theory and practice of making half-tone plates
> is fascinating. Its now almost a lost art, particularly the
> original method using cross-screens made of ruled glass.
>   The half-tone process was capable of very good quality
> when done right but it more often was not. The average
> quality of half-tone work done now is enormously better.
>   Until the 1950's the medium of choice was wet plate
> colloidion but it was rapidly displaced by self-screening
> film which eliminated the need for the cross-screen and
> special apertures. All done with computers and laser
> printers now.
>
> ---
> Richard Knoppow
> Los Angeles, CA, USA
> dickburk@ix.netcom.com
>
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