7.1

757
Color Correction Editor
Correcting Color Cast (with the Mouse)
You can correct a subjectively perceived predominance/lack of a particular hue quickly and easily using
linked Primary Color Correction:
1 Open the Color Correction Editor.
2 Click the clip you want to edit. It can be located in a Rack or on the Timeline.
If necessary, move to a specific spot in the clip using the position bar or the navigation buttons.
3 Assess the distribution of brightness and then click the Gain (highlights), Gamma (midtones) or
Black (dark range) button.
4 Take even greater control: Select the Ve c to r D i s pl a y (page 744) and, if necessary, activate the Lega-
lizer (page 751).
5 Drag the mouse pointer across the inlay in the direction of the hue that you wish to intensify and
away from the hue you want to soften.
The luminance remains the same. You can see how the linked values are changing by watching
the RGB bars.
Gray Balance (Subsequent White-Balancing)
To a large extent, the human eye is able to adjust to the predominant color temperatures of light. This is
why the same white object under different lighting conditions is still perceived as “white”.
A video camera must be set to the current definition of “white” before recording and when the light color
(color temperature) changes. If white-balancing was not done or was done incorrectly, it can still be cor-
rected subsequently - within certain limits, that is.
What is actually being done is Gray-Balancing because true white (255,255,255) seldom occurs. Instead
it’s a matter of taking an undesirable color cast in an area that is presumed “white” and changing it to
“achromatic”, i.e. a specific level of gray.
In the RGB model, “gray” is always produced when the RGB values are the same - for example (25,25,25)
or (111,111,111). In the YUV model, “gray” is when C
b
, C
r
= 0.
Consequently, Avid Liquid Gray Balance requires that gray be contained in the image motif. If it isn’t, you
might be better off using Tone Balance (page 760).
1-point gray balance
Æ How gray balance works (example) page 758
Æ Options page 759