Shooting in front of a green screen lets you swap in another background in post-production. Make the most of this technique with the right lighting.
Step 1: Set up the shot Set up the shot. Position the talent or stand-in as far from the screen as possible while keeping them in the frame. Place the lights for the screen behind or beside the talent to avoid shadows. Light the talent independently from the screen.
TIP: For full-body shots, lay non-green blankets or poster board on the floor around the talent to reduce reflected green light.
Step 2: Light the screen Once everything is in place, take the actor out of the equation. Diffuse the lights with gels, reposition the barn doors, and move the lights so the screen is lit as evenly as possible.
Step 3: Find hot spots Use your camera's "zebra" function to find hotspots. Close the iris; then slowly open it. If stripes appear in some patches before others, adjust the lights so the screen is illuminated more evenly. If the stripes appear uniform, you're good to go.
Step 4: Light the talent Turn the screen lights off and light the talent. Keep in mind the lighting needs to match the background that will be composited into the scene later. Additional lights and gels may be required; use any gel as long as it doesn't closely match the screen's hue.
Step 5: Turn it all on Turn all the lights on and make sure no green light is reflected on the talent. Reduce spill by adjusting or adding lights, or by moving the talent further away from the screen.
Step 6: Practice Practice lighting a green screen as much as possible in order to finesse your technique and get the best look every time. Now there's no limit to where your creative vision can take you!
FACT: The green screen technique, officially known as the chroma key process, also works with red and blue, but filmmakers don't use red because it's a dominant color in human skin tone.