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how does a green screen work? Why is it green? Answered

Like the weather-guy uses, the backround of the set is green so that they can use a computer to show images on the screen. Does the backround have to be green? Why green? It does not seem like a special color, i would think maybe white, red or blue?

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PAUL BURESH
PAUL BURESH

11 years ago

The green screen should be a more technical matter rather than some long
dissertation of what it does in Hollywood. A dedicated camera is aimed at a  green colored background and sends this information to a switcher or a chroma key device.  The switcher  receives the chroma  information from the dedicated camera that is producing a very high voltage output from the green  screen. This information "green" is now going to be compared to the switchers green color, and when both the switcher's color green and the camera's color of green are the same, but 180 degrees out of phase, the camera's color "green" is dissolved and is eliminated. Why did the green
color of the camera disappear?  When two voltages meet and are 180 degrees out of phase, the camera's green was eliminated allowing for
a matte or some other video to be super imposed as a back ground. If a
subject was in the dedicated camera's shot, all but the subject would remain. Just electronically removed to allow an overlay to be added later.
I hope this is helpful in telling why it works.

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PAUL BURESH
PAUL BURESH

Answer 11 years ago

I MISTAKENLY SAID, ALL, BUT THE SUBJECT WOULD REMAIN. I SHOULD HAVE SAID ALL IS GONE, BUT THE SUBJECT. THE SUBJECT REMAINS IN THE PICTURE. SORRY ABOUT THE TYPO  PAUL

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Joe Martin
Joe Martin

11 years ago

It's green I believe as bright green isn't really a common colour to wear.

If you want to try some chromakey use debugmode wax, It's free and you can change the colour of the key to whatever you want. Some great fun to be had if your bored

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kelseymh
kelseymh

11 years ago

Look up "chromakey" on Wikipedia.