The color of cinema.
If you’ve ever watched a behind-the-scenes special for a Hollywood blockbuster, you’ve probably seen actors performing in front of a green or blue background. But you don’t have to be a professional filmmaker to enjoy the benefits of a blue or green screen. Even if you’re an amateur shooting a short film in your backyard or a YouTuber making a tutorial video, hanging something as simple as a green or blue sheet in the background of a shot gives you the power to add stunning VFX during the post-production process by using a technique called chroma key compositing.
“In the old days with film, blue made it easier to key things. With digital cameras, green is more popular,” says filmmaker Charles Yeager. “But even in modern films they still use blue screens for specific reasons. There are pros and cons to both.”
What is chroma key?
“Chroma key is when you lock onto a specific color that’s different from anything else in the shot and eliminate it completely,” says director and cinematographer Steven Bernstein. “Sometimes that’s green, because it gives you the best separation. But we have the video editing technology to lock onto any shade of whatever color we want.”
Blue or green colors are popular backgrounds for filmmaking because they’re different from most human skin tones, hair colors, and clothing. This is why it’s important to make sure your actors don’t wear anything that matches the color of the screen behind them. For example, if an actor wears blue clothing in front of a blue screen, their body will be chroma keyed out of the shot along with the screen behind them. This is because the chroma key process keys out and removes everything that is the same color as the background screen.