Why do movie special effects use green as the background? Useful at home and abroad.

Because it is convenient for later technical synthesis, green screen is often used for special effects production and technical compensation to have a more comprehensive effect.

Colorful colors have their own characteristics, and there is a certain collection quality ratio between colors, including light. When applied to green, it is easy to form the physical and size characteristics of the image. For cameras, the green screen is easier to saturate, track and locate, and see through.

For production, the green screen has more imaging effect and color separation function. At present, mainstream special effects production does not necessarily rely on green screen technology like Avatar, and green screen technology is more suitable for making 3D movies. Movies like Transformers and Sparta 300 Warriors do not rely on green screen technology, and the effect is good.

Both the blue screen and the green screen are background screens for shooting special effects shots. Actors perform in front of blue and green screens and are photographed by cameras. The picture is processed in the computer, and the blue or green background is removed and replaced with other backgrounds.

Blue is the complementary color of human skin, and it should be the easiest to pick out images with a blue screen as the background. In recent years, the green screen is more used for stunt shooting. Perhaps the fluorescent green used in the green screen is easier to separate from the foreground in the computer system, which is brighter and less prone to black edges.

Blue screen is generally used in Asia, and green screen is generally used in Europe. Mainly because most Europeans' eyes are blue, if you use a blue screen, the eyes of the late actors will be easily cut off.

For example, the scene of the Monkey King walking in the TV series The Journey to the West was shot in front of the blue screen and changed into the background of the sky after processing. Of course, the technology is much more mature now, and it doesn't look so "fake". Now some movies in Hollywood are shot in front of a green screen, and there is no real background at all.

References:

Baidu Encyclopedia: Green Curtain