Quote:
|
Originally Posted by sanddrag
For greenscreening, one technique I've used is this special grey cloth (I forget what it's called) made just for this that hangs behind the actors/objects. Then a ring of 50 or so super bright green LEDs goes around the camera lense and points at whatever you are shooting with the camera. On the camera, this fabric reflects back green and shows up PERFECTLY EVEN with no shadows or anything, and the people don't look green at all. It actually gives them nice color. The only thing is it is kind of hard for the actors to stare into this ring of really bright LEDs around the camera lense.
|
What you are describing here is the Chromatte system. This is a pretty good system, however the screen can very easily reflect your key lighting and screw up your matte.
Speaking as someone who has to light chroma-key stuff at least twice a month for network television, I can give you a few pointers.
Number one, is not to actually light your background. You want to concentrate your lighting on your subject, and make sure they have ample backlight. Your backlight should be almost as strong as your key lighting (front lighting) The screen itself just needs a little bit of a wash. Also seperate your subject from the screen as much as possible.
A good setup is to have two keylights, 45 degrees from your subject both in the horizontal and vertical axes. Then have two backlights, mirroring your key lights. If need be, add some lower powered side-fill, and put a wash on the screen. Lighting is really the key to getting a good chroma key.
Also, make sure there are no wrinkles in the green screen.
Personally, I like using after-effects for keying, but there are lots of options.