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Re: Telecine Oral History Project...

I helped out with some work on color correctors myself some years back, and
got "warned" by our legal beagles to steer away from certain things or suffer

Two patents were involved in the color corrector suits.  The first, known as
the "Chromaloc Patent," started with the concept of connecting banks of
potentiometers that could be stepped through (the possibility of using a
digital computer to store and apply the corrections was mentioned) to make a
"color corrector" that could keep the colorplexer of a TK-28 film chain on
track while it was running.  The system was developed by Armand Sarabian and
his associates at the now-defunct Teletronics facility in New York City.  

The "Rainbow Patent," granted to Armand Sarabian (Corporate) in 1978, had
three features which went beyond Chromaloc.  These were: one, it could not
only reuse a previous set of corrections on a new scene, but it allowed the
operator to modify them if desired; two, it could apply an overall set of
modifications to a previously-made correction list, allowing the operator to
compensate for machine drift over time; and three, it allowed for individual
hue and saturation adjustments of six color vectors (primaries and
secondaries).  In a more or less black-and-white decision, the judge
determined that Rainbow was valid because none of the "prior art" such as
Chromaloc, BBC's "TARIF," RCA's Chromacomp, Philips' Variable Matrix, or
Telemation's CF-3000 had those specific features.  In what has been referred
to as the Rainbow suit, Dubner color correctors at Columbia (EUE Screen Gems
and Editel) were held to be infringing because they had secondary color
correction.  Columbia Video Cassettes' facility, which had a TOPSY, was also
held to be infringing because it had the ability to recall and reuse prior

Interestingly enough, facilities I've worked in that had or were still using
Dubners also had RCA Chromacomps (used for the secondary corrections) in
them.  In all cases, the Chromacomps had been ripped out and dumped in
storerooms.  Apparently, if you had a non-Corporate color corrector with
secondaries, you were given a choice: either pay a license fee and continue
to use them, or permanently disable them.

In a separate suit, Dubner, Ampex, and all other manufacturers of
computer-controlled color correctors were held to be infringing, based mainly
on the earlier patent.  At this point, Corporate not only sought damages and
license fees from the manufacturers, but from anybody who used a
computer-controlled color corrector for commercial gain.  The only way to
avoid paying damages (as an end user) was to scrap whatever color corrector
you were using and buy a Corporate.  Although Dubner probably could have
obtained a license and stayed in the color corrector business, they got
disgusted and opted out, and Grass Valley Group, which bought the company
five or six years ago has done its best to forget the whole thing.  As far as
I know, Ampex bought back the few color correctors it had sold and
sledge-hammered them out of existence.

Was this a set back in the development of color correction technology?  It
may have kept a few people from dabbling in the business, but other than
that, I don't think so.  All analog color correctors work pretty much the
way, except for the control panels.  It's only been within the last few years
that they've each gone off on their own digital paths, and that required
technology that wasn't even dreamed of until recently.

Christopher "imitation is the sincerest form of plagiarism" Bacon