Green Screen and Chroma Keying

A clean key starts with proper lighting on set, not in post. The green screen must be lit separately from the subject, evenly and without shadows—a variation of more than 10% in luminance across the screen creates keying problems. Use soft, diffused lights positioned at 45 degrees to the screen. Keep the subject at least 8-10 feet from the screen to prevent green light bouncing onto them (green spill). Light the subject with the color temperature and direction that matches the intended background plate. If the final composite shows the character in a sunset scene, light them with warm, directional light from camera-left—mismatched lighting is the #1 reason composites look fake.