[QuadList] [Quad List] Question of the week-RCA AE 6000 editor/TEP

Wed Mar 9 09:30:29 CST 2011

Doing this "shift" provided the cleanest sharpest image because it was a
composite image. Chroma and image were really one and not separate.
Separating the chroma from the luminance was indeed possible but flipping
the chroma on top of the luminance required some form of filtering which did
alter the picture. What the Zeus was able to do is run in the "filtering"
mode all the time so chroma flipped or not, always looked the same.  But I
will say the filtering was "really" good so the normal image, even while
filtered, looked great.  It was not the same exact image as as the
unfiltered ones.  Note this same type of filtering was required when slowing
down the image since fields had to be flipped necessitating the need to flip
the chroma 180.  So this was a normal process for every machine that could
slow the picture.  You could easily see the results of this on a Sony when
in jog or slow.  But it was considered acceptable and necessary at the time.
These were the tradeoffs for composite video.  

Gary 

-----Original Message-----
From: quadlist-bounces at quadvideotapegroup.com
[mailto:quadlist-bounces at quadvideotapegroup.com] On Behalf Of Wayne Watson
Sent: Wednesday, March 09, 2011 10:10 AM
To: Quad List
Subject: Re: [QuadList] [Quad List] Question of the week-RCA AE 6000
editor/TEP

So my understanding is that the "TBC" of the day moved the luminance only
140ns to match the chroma and that was the small hor shift you saw (on match
frame only edits). I think later the Ampex Zeus was the only TBC to know
about this and "fix" them. I think it was a mode you could turn on the
prevent this problem.

Wayne Watson

-----Original Message-----
From: quadlist-bounces at quadvideotapegroup.com
[mailto:quadlist-bounces at quadvideotapegroup.com] On Behalf Of David
Crosthwait
Sent: Tuesday, March 08, 2011 6:15 PM
To: Quad List
Subject: Re: [QuadList] [Quad List] Question of the week-RCA AE 6000
editor/TEP

Trevor and Tony,

A half-cycle of subcarrier (H shift) is 140 ns. here in NTSC land. 

Been there, done that...

David
www.dcvideo.com

On Mar 8, 2011, at 1:31 PM, Tony Quinn wrote:

> In message <003101cbddd6$f30f09e0$d92d1da0$@com>, Trevor Brown
<videovault at sky.com> writes
>> Tony I bow to your mathematics it's a long time ago
>> Was it not 1/4 cycle of subcarrier ?  4.43361875 Mhz
> 
> Half a cycle ... It resulted in Colortec going (effectively) from one end
to the other)
>> 
>> It's a small picture jump that you get away with on cuts
>> 110 or 112.7 its equally annoying
> 
> Only on invisibles, if there's as change of picture content it becomes )to
all intents and purposes) invisible
>> 
>> Colortec ??? CATC   :-(
> 
> Yes - but I have very limited experience of RCA kit - VT24 was about my
limit -  I would never, due to grades at the time, have been allowed into
Suite 2 (Rip. Scratch, and all that)
> -- 
> If one person has delusions, we call them psychotic. If, however, 1.5
billion
> people have delusions we must apparently call them a religious group, and
> respect their delusionary state.
> 
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