Why chromakey is green?

Chroma key is the technology simplified to combine multiple images in one frame. This technology used in television, film and video production. Chroma Key allows you to remove a green background and superimpose any image on its place.

The editor in the special application chooses the command “delete all green pixels”, and the system will automatically replace them with another image, most often with computer graphics. The background color can be any color, even red (the main idea — color should not coincide with the object in the frame), but video production usually used green.

Green background color is widespread not by accident. The fact is that the matrixes based on the Bayer filter, which are used in modern digital cameras, are more sensitive to green shades. So, the image in the green channel is cleaner, contains less noise — all this greatly simplifies its subsequent processing. And the blue color of the chromakey has receded into the background for a rather banal reason — because of the blue-eyed people and blue jeans that often flash on the screen.

By the way, there are films that are almost completely made using a green background. For example: “City of Sins”, “Avatar”, “Alice in Wonderland” or “Life of Pi”. In some cases, the substitution is quite obvious — they cannot shoot all these cosmic, unreal landscapes from nature! But sometimes we don't even notice this substitution...