The History of Green Screen

The Green Screen has been used in news rooms, music videos, and films for many years. Green Screen or “Chroma Keying” is a special effect usually implemented in post (unless you do live news). The technique composes, or layers, two images or video streams together. The color green used on green screens is based on the Chroma Range that allows this technique to remove the top layer (green) and replace it with another image behind it.

Green screens are green because the particular hue of green is not naturally found in most clothing or everyday modern styles. Green screens can also be blue, since blue is another color easy to remove and layer. However, blue is typically found in most clothing and therefore more troublesome to work with when dealing with live news. If the weather caster wears a color too similar to the color of the green/ blue screen their clothing will be replaced with the background video.

From my experience working at NBC there has only been one incident while I was present with the clothing option of our weather girl and the green screen. She had worn a dress with a lime green/yellow color block on the front of the dress. She had no other clothes to change into and her whole chest had disappeared on air. In order to solve this situation she chose to do all of her casting from the weather center and going in to what we call “graphics” which is what would be on the green screen without her being on camera.

Before the implementation of the green screen in weather forecasting the forecaster would stand in front of a wall with a large map on it a use magnets or similar devices to show the weather manually vs. the highly technological way we use to show the weather now.