If you’re planning on having a video production company produce a short Web video for your website, be prepared for a flurry of behind-the-scenes activity. After all, there’s much more involved than lights, camera, and action. When you arrive at the studio, you may be surprised at the lack of a set. In its place, you may see a gaudy green screen.

What Video Green Screens Do

The green screen may be bright and unattractive, but it serves an important function. This green color can effectively be removed from the video and replaced with other images. For example, when you watch a television weather reporter standing in front of weather maps and radar images, the weather reporter is actually standing in front of a green screen. In the television control room, a technician uses a switcher equipped with what’s known as “chroma key” technology to replace the green with a computer generated image. If you’ve ever watched the Suze Orman Show on television, her entire set is chroma key green and computer generated.

Why Chromo Key Green?

Theoretically, you could use chroma key technology with other colors. However chroma key green and chroma key blue are the most popular. These garish colors aren’t commonly used in clothing and props, making them a good choice. Remember, the technology finds all instances of the selected color whether the color is painted on the set or worn as clothing. If the onscreen talent were to wear a chroma key green necktie, that necktie would be replaced with the video intended to appear on the screen behind the talent.

The Green Screen and Online Video

While green screens are commonly used in broadcasting, they’re also used for Web video. If you want a unique background or a polished “broadcast-like” look, shooting your Web video in front of a green screen and replacing the green background with a computer generated or b-roll video background can accomplish that.

Another use for chromo key in the Web video realm involves virtual spokespeople who are superimposed over the actual website. In this case, the chroma key technology doesn’t replace the green background with a new image; it removes the background completely. With a transparent background, only the actor or actress appears. This allows for frameless video overlays and creates the illusion of the actor being a part of the website itself.

When you head to the studio for your next video shoot, don’t be surprised if you’re placed in front of an ugly green screen. If you’re curious, ask the director to show you the composite picture before or after the shoot and enjoy your time behind the scenes!