This article credits the first Christopher Reeve Superman movie as spawning the change for obvious reasons--Superman's blue suit risked him appearing invisible in front of a blue screen! This is because digital cameras retain more detail in the green color channel. Additionally, green screens typically require less light to properly illuminate. However, both of these colors share a similar trait: unless you're videotaping an Andorian or an Orion, flesh tones don't contain blue or green. Which is why they remain the two most popular colors for chromakey, even though many of today's chromakey programs use a Photoshop-style eyedropper to set their keys, and can key from almost any color.

Learning The Keys To Chroma

John Jackman's Bluescreen Compositing, published by Focal Press, is a great place to begin to learn the keys to chroma. Jackman, the head of an independent film production firm with over 30 years experience, starts the reader out at the beginning with the technology of yore--Hollywood's blue screen film effects of the 1950s through the original 1977 Star Wars, and the first green screen chromakey systems for video in the 1970s. Jackman's book then quickly moves on, to the various software keyers built into today's popular video editing programs.

These chapters serve as both an overview as to what's out there, as well as a hands-on instruction to getting the best keys from these various programs and applets. A DVD-ROM attached to the book sleeve provides footage for use in these tutorials.

Also included is a chapter on hardware-based keyers, which are popular in studios for live use behind those still ubiquitous TV weathermen.

By the end of the book, and through experimentation with its tutorials, you should have the chromakeys to the highway, whether you'd like to produce The Longest Day with three friends, or become a one-man video news producer.

The Joy Of Virtual Sets

Once you're able to pull off a decent key, it's now possible to put your on-screen talent (or yourself, if you're a one man video band) into all sorts of unique settings, as I did in the above video. In the past television productions required a dedicated studio. Now for about $2,500 for software, lighting kit and a green screen backing, it's possible to "build" a virtual set that looks like it costs a lot more than it does.