Primary Color Correction: Tonal Range Primer - The Art and Technique of Digital Color Correction - page 28

(a) (b)

Fig. 1.26 (a) The resulting RGB Parade with a good spread between highlights and shadows. (b) The resulting image with the highlights
and shadows spread out.

the shape of the top of the waveform stays flat, then the clipping occurred
before it was brought in to the color corrector, probably during shooting.
When the maximum gain is reached, it may have affected your black
levels, so adjust them a little bit to get them as close to 0IRE as possible
(assuming that your video signal is not set for 7.5IRE) without “crushing”
any detail. Remember, we don't want to see the highlights or the shadows
flatten out on the waveform monitor for now. The goal is to spread the
tonal range from 0 to 100IRE.
Also, the shapes in the trace representing the brighter portions of your
picture that are not already clipped will start to compress. Unless you are
going for a specific “look,” this clipping, flattening, or compressing is a bad
thing. It means you are losing detail in those bright portions of the picture.
This result is similar to the issues we discussed while setting black levels.
When you start to see this “flattening” in the waveform monitor, try to

Making color correction adjustments is like focusing a camera.

find the corresponding part of the image in the broadcast monitor and lift,
then lower the gain while you watch the actual image ( Figure 1.26 ) . Do
you notice the point at which the highlights begin to lose detail? Remem-
ber that camera focusing analogy here, too.
If you don't have a limiter on your software, then the highlights can be
adjusted far above “legal” without the waveform showing clipping (this
may depend on your software or your settings in your software, to some
extent). However, at some point in the broadcast or duplication or dis-
tribution chain, these super-bright highlights will get clipped. It's much