Here's my input clip loaded and ready for work. The white squares are the selected points to create a color range for the key. (click to enlarge)

When I click on Enable, here's what happens - voilĂ  - the green background disappears. I also tweak the brightness, gamma, contrast and other sliders slightly to adjust the image more to my liking. (click to enlarge)

Now I add the background clip with the original green background still in place, make some additional adjustments and see the results on the preview screen at right. It's fair to say that I'm beside myself here, having lots of fun with my chromakeys! (click to enlarge)

Here I am in front of the famous Hollywood sign, and I never left my driveway in New Jersey! This is one of the many stock background images supplied with Adobe Ultra CS3 that you can use. (click to enlarge)

Changing my location from Beverly Hills to the plains of the Serengeti at dusk is as simple as loading another background image. Adjusting the light and color settings of the foreground image can help you match the background better. (click to enlarge)

Here I loaded one of the virtual sets - the museum. The B on the left image of the virtual set thumbnail denotes an area that can accept an inset image. I adjusted the color control and post-processing sliders to make my outdoor footage work with this indoor virtual set. (click to enlarge)

I put video footage in the B (Source B) inset, just to illustrate what it is possible to do here. (click to enlarge)

And here's the same virtual set with a static image of a vintage Indian motorcycle instead of video in the B inset. (click to enlarge)

Here's an image of my dog, Major, inserted into the B inset for another scene using the museum virtual set. I added some shadows (look at the sliders) to make the composite image a bit more convincing. (click to enlarge)

This is a composite of me in front of my house, but I need to adjust the lighting to make this look a bit more natural. And that's easy to do using the sliders. (click to enlarge)

An example of mixing new digital (foreground) footage with converted Hi-8 analog footage (background) shot in Rachel, Nevada, back in 1995. (click to enlarge)

In the background, here is a still image of Survivorman Tom in the woods of New Jersey with the foreground composite footage placed low and to the right. (click to enlarge)

The foreground can be moved and placed anywhere you want it over the composited image, as I'm showing here, by using the Position in Scene control. You can also alter the orientation of the keyed image, if desired. (click to enlarge)

Here it is moved to the lower left over the background image, so you have plenty of creative flexibility and choices. (click to enlarge)

What I've shown and discussed here barely scratches the surface of the creative things you can do with chromakeying. As you learn more by doing, your skills will get better and so will your composited productions. Have fun!

Tom Benford has been writing about video, photography, filmmaking and myriad other subjects for over 30 years, and he has authored more than a dozen books.

To view the tutorial video for The ABCs of Chromakeys, click here.