|
|
Posted by nobody special on 10/05/06 11:37
Alex, it might be trying to luminance key off the white, which is what
they used to do in the 50's and early 60's before chromakey. You need
to double-check your camera hookups,a dn make a real green screen,
before you go any further, go buy a 2-dollar (or is it 2-looney?) piece
of he neon-green-looking posterboard available at the corner drugstore
or office supply place. You could also go with blue for chromakey, and
in your situation, that may be more useful. The blue, you could stand
in front of *without* using the keyer, and still have a pleasing
backdrop.
But start small, with a 2x3 foot or so piece of the posterboard. Stick
any old thing in front of that for the test subject, long as it doesn't
have a similar color.
Chromakeys, especially on cheap gear, demand very even lighting. Make a
softlight if you don't have one already, and use the zebra bars
function in your camea viewfinder eyepiece to see if the intensity is
very similar all the way across the green panel. If you don;t have a
softlight, you can make one by making a large tapered box out of foam
core sheets and gaffer tape, attaching it to the barn doors of a
regular video light with wooden clothes pins or metal bulldog clips,
and laying a diffusion material like tough spun or translucent vellum
over the front of the box. More detailed info and safety tips at
vidpro.org under the "cheap tricks" section.
White balance the camera to the light and a white or light gray card,
on the "indoor" filter, before you proceed with the green screen work.
Turn off any other room lights that may be a different colot temp, like
overhead flouros or incandescents, and of course, no daylight allowed
to mix in. Turn off the camera's auto-tracing white balance and
auto-iris. Now make sure you followed the hookup directions correctly
for the switcher; some switchers will only chromakey off a live source,
not a taped one. Roll some tape and try importing the footage into
your NLE editing system of choice to see if it will key at all well in
there. That will tell you if you're in the ballpark for the switcher
live version.
Finally, a great resource for you is at www.dv.com in the forums
section. Ask your questions in the lighting and effects/editing/camera
forums, or if you're shy, search the site's archives for TONS of great
info on everything you need regarding chromakeying.
Navigation:
[Reply to this message]
|