Primary Color Correction: Color Control Primer - The Art and Technique of Digital Color Correction - page 84

The RGB Parade waveforms for the two different Art Institute shots
are basically unbalanced in opposite directions. The warm one is strongest
in the reds and weakest in the blues ( Figure 3.15 ) . The cool one is weak-
est in the reds and strongest in the blues ( Figure 3.14 ) .
I like the warm look, but if we want to, we can correct both of them
to a more balanced, neutral, grayer, “urban” feel. With the lift balanced
and lowered in either shot, simply use the RGB gain controls to make the
tops of the RGB Parade color channels match at around 80 or 90IRE or
percent.
There are some bright highlights in the stairs at the bottom of the pic-
ture, but they probably shouldn't be pure white. You may prefer to bal-
ance the highlights at some level higher or lower than I did. To make that
determination, you'll need to look at the image in the picture monitor to
decide when it starts getting too bright.
To execute the more neutral balance—instead of trying to match the
warmer image—set the red gain levels to match the green gain levels.
Look at the various shapes in the waveform of the red and green chan-
nel and see how closely you can get them to match with the red gain
control.
Now use the blue gain control to match the blue highlights back to
where the red and green channels are. At this point, the clipped areas
of the sky are around 100IRE for red, 95IRE for green, and 85IRE for
blue. This is not a good color for the sky. We'll show you how to fix this
problem in the secondary section of the topic. For now, we're trying to
complete those basic, primary color corrections.
You should realize that a primary color correction is often done to
get most of the image looking good, even if it means that it takes another,

Fig. 3.14 The RGB Parade for the uncorrected warm Art Institute
shot.

Fig. 3.15 The RGB Parade for the uncorrected cool Art Institute
shot.