Murphy is going to show you how to make elements in your movie vanish from the screen. Here are the basics: Put your camera somewhere it won’t move, like a tripod. Film your subject in motion. Let the camera keep rolling and get a shot of your background without the subject.
In iMovie you’ll do a simple Cross Dissolve from the clip with your subject to a clip or still of just your background. The subject will gradually fade out and disappear from the movie.
This works great with something like kids running across a field or skiing or jumping rope – or just about anything.
Click below to learn how in the screencast. You can download the Quicktime output too.