How do green screens work?

Answer 1

===It's very simple actually. A green screen is a large green sheet that goes on the wall. When a person films a video in front of a green screen, they put it in an editing software with chroma key. Chroma key is the removal of a single color, therefore when chroma key is activated, the green gets removed, and ANY background gets inserted. That's why you can not wear green against a green screen, because if you wore a green shirt for example, it would be invisible and you would see the background you inserted instead of your shirt. Basically you can do "green screening" with any color, but green and blue are the furthest away from your skin color. That's so your skin isn't invisible If you did a white/black screen, there's a good chance your skin would be invisible That is why they use green. Hope that answers your question !! =) === A more technical explanation about this topic would be helpful. A dedicated color camera with RGB output is focused on the painted green screen wall. Such as you would find in a TV weatherman's studio. The green color that the camera sees, is sent to a switcher that has chroma keying abilities. Once the chroma keying is turned on, two adjustments are usually set for dissolving the green from the video. First, a range of colors on the switcher is adjusted to find green. the other control is adjusted to find the saturation of the color green. Now the green color should be dissolved and a blank screen seen. What has happened to the green color. In electronics, when two voltages are generated and come together 180 degrees out of phase, they cancel. When the camera provided one voltage, and the switcher provided an identical voltage, but 180 degrees out of phase, cancellation occurred and the video is now sent down stream where an overlay may be added, such as a states weather map, or any other video..

Answer 2

Lets say you have a scene were your actor is on a cliff screaming, but you are no where near a cliff. You tape a green screen (a green table cloth from kmart will do) to a wall, and have the actor do his thing. Then in an editing program like iMovie, final cut, or after effects, you can replace the green with a cliff. Just make sure the actor is not wearing green.

Answer 3

The green or the blue is erased in a computer editing program. In its place, you insert what's called a "background plate". The background plate may be footage filmed on another location, stock footage, CGI, or any other sort of video/image.

Answer 4

First, video is captured digitally or on film. After converting analog film to digital, or uploading digital video to the computer, film producers use film editing software to replace the green screen with a different desired image. Green screen can be used to create a wide number of effects: flying or other movement, complete digital sets, or insertion of completely digital extra characters.