It depends on what you are trying to do and what you want the end result to look like.
If you want your talent in a white limbo background, then shooting over white is ok, then use a luma key to clean up any dirty parts.
But if you want to put your talent in a
different environment (an office, a meadow, or just over some background plate), then I would
never use white as a background.
Blue or green are used as key background colors because they are most opposite of skin tones. White, on the other hand, contains
all colors.... 100% of blue, red, and green. If you try to
chromakey it, you'll get a very dirty key indeed. At least
chromatically your talent in the gray suit is exactly the same
color as your background... even amounts of RGB... just not as much of it. Your only choice would be to luma key it, and it's still likely going to look pretty ragged.
If you
have to go the lumakey route, your better bet would probably be putting them in a pure
black environment rather than white... which would allow you to light your talent in a more refined way, independent from a glaring white background that might give you a fair bit of unwanted spill.
I do luma keys on occasion when appropriate... but putting human talent in another environment is definitely a case for greenscreen or bluescreen.
T2
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Todd Terry
Creative Director
Fantastic Plastic Entertainment, Inc.
fantasticplastic.com
