Chroma Key Effects: Making an Invisible Man
Through the use of chroma key effects, a green suit and tools such as Ultimatte, creating an invisible man has become much easier and cheaper. It involves a technique referred to as chroma key compositing, green screen or blue screen. This technique involves combining images from different sources and merging them into one seamless image.
Using this technique, the subject is placed in an area with a flat green or blue screen. The background is removed and replaced with another image during the editing process. In earlier times of filmmaking, the acquisition and use of green screen technology was limited to larger production companies because of the amount of money involved. The following steps will help filmmakers create their first invisible characters.
Step 1: Purchase a Green Screen and Body Suit
Green screens have been commonly used in film productions, where the background needs to be replaced for creative or practical reasons. With newer materials, it is possible for independent or student filmmakers to purchase or create their own green screen for a cheaper price. Some possible alternatives include using paper, cardboard, wood or wall painted green.
A green body suit works in the same way as a green screen. The subject or actor wears a full body suit, which is in the same flat color as the background. As the both the screen and background are in the same hue, these can be easily removed during editing. Besides green, the suit also comes in blue to fit blue screens. Select a color for the suit that matches with the screen. Bear in mind that these must not be in the same hue as with other elements being used in the shot, or these may be removed during editing as well.
Step 2: Illuminate the Green Screen Scene
With using a green screen and body suit, lighting is important. The light must be as even as consistent as possible. Shadows should be avoided at all costs, as this would make removing the green screen and suit more difficult during editing. Start with providing even light to the green screen then adding the subjects. The distance between the subjects and the screen will need to be adjusted, as well as the direction and intensity of the lights to make the best compromise of consistent illumination. A large area and green screen is often needed to make the adjustments easier.
Step 3: Experiment with Different Backgrounds Using Ultimatte
The traditional way of removing the green screen is through post production or the use of video editing programs. With the Ultimatte, a filmmaker can see the effects even while shooting the scene. The Utimatte is a device which can be attached to the camcorder, monitor, computer and even a DVD player.
Compared to other devices, the Ultimatte allows the filmmaker or director to add the background and see the effects without the need for additional editing equipment. The controls on the Ultimatte can be used to edit and modify the green screen background to make replacements much easier. The device also acts as a transcoder, allowing the user to convert between several different video formats.