Posted by Richard Crowley on 01/11/90 11:50

"Jeff_BTFP" wrote ...
>I do concert video (projection/to tape), and had a question regarding
> an effect I saw on TV last night, and what it's benefits are.
>
> The show used a lot of moving lights, and I noticed in certain
> situations when the moving light was pointed directly at the camera, a
> black spot would appear in the middle of the light source (lamp). I
> interpret this as some kind of a Luma Key.

Not necessarily. It could be an artifact of the camera pickup
device, or the circuitry anywhere along the line. Sometimes if
something is TOO bright (like the very center of a light aimed
directly at the camera, the brightness "folds back on itself"
and appears to be black. Or sometimes this shows up as a
vertical streak (black or white) from the bright spot all the
way to the top of the picture, and all the way to the bottom.

> What are the benefits of using this? Is this just some piece of
> hardware the network puts in place to make sure that the video is
> broadcast safe??

Dunno of any "benefits"? In fact it can be rather dangerous in
terms of the camera pickup device (tube/solid-state sensor).
For the same reason you shouldn't look at the sun, etc.

> As you can tell, I know very little about TV Broadcast....If you could
> help me out or point me to a website that goes more in depth, I'd
> appreciate it greatly.

Not sure exactly what you are asking?

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