440 Chapter 20 the process of Digital editing Figure 20-30 Source Code (Jones) used a simple green screen effect to create a moving background for a stationary train set built on a sound stage. (See the color insert). 2) Light your subject in a way that matches the background image. 3) Be careful that there are no reflective surfaces on the set or subject (like eyeglasses) that will catch the chroma color ­ these patches will also key-out. 4) Keep your subject five feet or more from the 5) Avoid set and wardrobe colors that are close to the key color. The Voice & Vision example short film The Black Hole by Phil and Olly uses a green key to create the "black hole special effect." Can you figure out how it was done? See the film and then check out the