Apple Final Cut Pro 5 - Manual (Page 1177)

390 Part II Project Interchange
Using the Final Cut Pro Video Scopes to Help Correctly Light
Your Background Screen
Since the Waveform Monitor shows you all variances in brightness in the video frame
from the left to the right of the screen, you can use it to reveal hot spots in your
background screen that may be difficult to see with the naked eye. If you connect
your PowerBook to a DV videocamera with FireWire while you’re on the set, you can
see the brightness level across the entire blue or green screen background on the
Waveform Monitor’s graph. (You can also use an analog-to-DV converter to connect
to the analog output of a camera with a different format.) Hot spots appear as spikes
on the Waveform Monitor, and shadows appear as spikes, while shadowed areas
appear as dips.
With this information, you can adjust your lighting until it appears even in the graph
in the Waveform Monitor, ensuring the best possible background for keying. Once
your lighting is adjusted, you can perform an additional test by capturing a clip, and
then using the Chroma Keyer filter to see how well it keys.
Spike
Shadowed dip