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Posting-Version: version B 2.10.2 9/18/84; site onfcanim.UUCP
Path: utzoo!watmath!watnot!watcgl!onfcanim!dave
From: dave@onfcanim.UUCP (Dave Martindale)
Newsgroups: net.graphics
Subject: Re: Film Recorders
Message-ID: <14752@onfcanim.UUCP>
Date: Wed, 13-Nov-85 10:35:37 EST
Article-I.D.: onfcanim.14752
Posted: Wed Nov 13 10:35:37 1985
Date-Received: Thu, 14-Nov-85 07:15:20 EST
References: <471@sdchema.sdchema.UUCP> <648@dicomed.UUCP>
Reply-To: dave@onfcanim.UUCP (Dave Martindale)
Organization: ONF, Montreal
Lines: 34

In article <648@dicomed.UUCP> papke@dicomed.UUCP (Kurt Papke) writes:
>A brief overview of the Film Recorder marketplace:
>
>	Manufacturer/model	Price	Comments
>	Celco			$150k	4k, newly introduced 8k
>	Dicomed D48		$250k	4k/8k

A comment on "8000-line" film recorders:  The newly-introduced "8k" resolution
Celco is not new at all.  The CFR-4000 already had a 13-bit vertical DAC
and so could plot 8000 lines; calling the new model the CFR-8000 is just
marketing.  The real difference is that the 8000 mounts the electronics
in a full-height rack, rather than the stubby rack designed to fit under
a table.  The older Celco was called the "4000" because its useful
resolution was on the order of 4000 distinct lines - this is limited by
CRT spot size, not DAC resolution.  I believe the primary reason for
plotting 8000 lines was that if you plotted on very large sheet film
(8x10) you could start seeing spaces between the lines if you plotted
only 4000.  But you still couldn't resolve 8000 distinct lines, since
the CRT image isn't sharp enough.

The Dicomed, I believe, has 15-bit vertical and horizontal DACs.  These
allow precise formatting of the on-screen shape of "pixels" and allow the
drawing of very smooth vectors.  But the number of pixels it can resolve
on screen is also in the same range as the Celco's - again limited by
CRT spot size.

>There is obviously a wide discrepency between the price at the bottom of
>the market, and that at the top.  This arises from the cost of pushing the
>performance envelope in the 8k region -- film recorders are complex
>electro/mechanical/optical devices.

The amazing thing is how well they are built.  Our Celco seems to use
mostly military-spec parts.  The weakest link in both the Celco we
have and a Dicomed I've seen is the camera.