Green Screens: The History and Science of Chroma Keying

Green screens are ubiquitous in modern filmmaking, allowing filmmakers to create spectacular scenes that would be impossible or impractical to shoot in real locations. But what are green screens, how do they work, and when did they start to be used? In this article, we will explore the history and science of chroma keying and the technique behind green screens.

What is a green screen?

A green screen is a large, flat surface that is painted or covered with a bright green fabric or paper. It is placed behind the actors or objects that need to be filmed, creating a uniform background that can be easily replaced with another image or video in post-production. This process is called chroma keying or compositing, and it involves isolating the green colour from the original footage and making it transparent so that the desired background can be inserted behind the foreground elements.

Why green?

Green is not the only colour that can be used for chroma keying. In fact, any color that is distinct from the foreground elements can be used, as long as it does not appear in the subject’s skin, clothing, or props. However, green has some advantages over other colours, such as:

• Green is the color that digital cameras are most sensitive to, due to the way they…