Apple Final Cut Pro 6 - Manual (Page 1328)

Chapter 26 Measuring and Setting Video Levels 543
III
6 Now, turn the contrast all the way up so that this bar becomes bright, and then turn it
back down.
The point where this bar is barely visible is the correct contrast setting for your monitor.
(The example shown below is exaggerated to demonstrate.)
Note: The contrast control adjusts how much the RGB signals are scaled.
When adjusting the contrast, also watch the white square in the lower left. If the contrast
is too high, the white square appears to “spill” into the surrounding squares. Adjust the
contrast until the luma of the white square no longer spills into surrounding squares.
7 Once you have finished adjusting luma settings, turn up the chroma control to the
middle (detent) position.
Note: Some knobs stop subtly at a default position. This is known as the detent position
of the knob.
When monitor brightness and
contrast are properly adjusted,
this strip should barely be
visible above black.