Apple Final Cut Pro 5 - Manual (Page 322)

23
321
23
Using Color Bars
for Video Calibration
When using analog devices, make sure they are
calibrated for accurate brightness and color so
there’s no distortion when you capture and color
correct your video.
This chapter covers the following:
 Using Color Bars (p. 321)
 Calibrating Brightness and Color on Analog Equipment (p. 322)
 How Digital Video Levels Are Measured in Final Cut Pro (p. 323)
 Measuring Analog Video During Output (p. 325)
 Using the Waveform Monitor and Vectorscope (p. 325)
 Outputting Accurate DV Black Levels Using FireWire (p. 330)
 Using an External Waveform Monitor and Vectorscope to Calibrate Analog Video
Levels
(p. 330)
Using Color Bars
Color bars are an electronically generated video signal that meet very strict
specifications. Because the luma and chroma levels are standardized, you can use color
bars passing through different components of a video system to see how each device
is affecting the signal. For example, suppose you record color bars that have a 100
percent white level in a camcorder, and then play the videotape back on a VTR. If the
white level output from the VTR is only 90 percent, you need to increase the luma level
output of the VTR.
You should only evaluate color bars using a calibrated video scope, such as a waveform
monitor (which measures video luma—the black and white signal) or a vectorscope
(which measures chroma—color saturation and hue). Judging color bars by eye is not
particularly helpful, except in the broadest terms: If a red color bar has turned green,
you know your equipment needs to be adjusted, but you still need a scope to correct
the problem precisely.