283 Tips for effective color or chroma key shots Chroma key video shoots don’t always go smoothly. For the key effects to work
effectively, you should follow these tips:
t Use flat lighting (two lights at 45° angles to the screen) to avoid creating hot
spots. Don’t overdo the lighting. Simply make it even.
t The actor’s lighting does not have to be flat. Controlled spotlights or lights with
“barn doors” work well.
t If you’re going to key in an outdoor background, use daylight-balanced blue
gels over your lights to re-create outdoor lighting, or shoot your chroma key
shots outdoors. If you’re working with live actors, use a fan to blow their hair
around to enhance the illusion.
t Avoid chroma key spill—keep actors at least 4 feet away from the backdrop to
avoid picking up its reflected color. A backlight on the actors minimizes spill.
t The tighter the shot, the more realistic the finished look will be.
t Fast-paced action is harder to key right to the edges of your subjects.
t Use a wide-open iris on your camcorder to limit the depth of field and to throw
the blue screen or green screen a bit out of focus, making it easier to key out.
t Chroma key fabric and paper cost about $8 a square yard, and paint costs about
$60 a gallon. You can find many dealers online.
t Which color should you use? With chroma key green, you have a reasonable
assurance that no one will have clothing that matches it, and therefore it will key
out. Chroma key blue works well because it’s complementary to most skin tones.
t Consumer and prosumer camcorders do not key as well as professional
camcorders because they record less color information. However, because
they give more weight to green colors to correspond to the color sensitivity
of human eyes, green screens key more cleanly than blue.
