Many big-scene science fiction movies will use green cloth as the background, and special effects will be produced later. So why do they choose green instead of other colors?

First of all, both colors are solid colors and are not easily disturbed and affected. Secondly, keying photography is basically about people. Considering the skin color of people, no matter they are white, black or yellow, their skin has red and yellow information, which is not conducive to keying, so red and yellow are not used. Furthermore, since the eyes of Europeans and Americans are generally blue, for the sake of convenience, Europeans and Americans tend to pick out green images, and of course they often pick out blue. Chinese people have black hair, black eyes, and yellow skin. They can pick out blue or green, but in order to get greater contrast, they usually pick out more green.

In fact, blue was also used in the past. Blue and green are easily recognized and removed by software. To put it simply: the software identifies green (or blue) pixels and then removes them, leaving a transparent channel. , you get a character material without a background, and then you can use outer space or an ancient castle as the background.

The basic structure of film is composed of three layers: red, green, and blue. Basically, red, green, and blue can be used as background colors, which can be understood as these three colors. It is the matrix of color.

Green has its own advantages. There is obvious adaptability when working on the mask part when there are blue objects in the foreground. Green has a significant reflectance and is easier to paint than blue during masking. At the same time, video cameras are normally more sensitive to the green channel, and the best resolution and picture details are generally in the green channel.

So, generally technology blockbusters with strong special effects use green background cloth.