Primary Color Correction: Tonal Correction Tools - The Art and Technique of Digital Color Correction - page 58

the graph kind of split the difference with a 40-point difference. So you
can see that by lowering the shadows, we've also already lowered the
midtone values somewhat.
You don't need to pay too much attention to the waveform moni-
tor as you adjust the gammas. There's not much that they can tell you.
Sometimes, if you adjust the gamma enough, you will create clipping
or illegal levels in the shadows if you lower the gamma a lot or in the
highlights if you raise the gamma significantly, but as we're pretty close
to the correct level for gamma, all you need to watch is the same detail
areas we were monitoring before when we were concerned with setting
the shadow (black) level. Watch the eyes and hair for loss of detail and
the skin tones for richness as you lift or lower the point in the middle
of the line. You can also move the middle point left or right. The move
in the blacks richened up a lot of the midtones, and the move in the
highlights brought down the overall levels as well. Because of this, even
though I usually end up pulling down gammas to richen up the image,
with this one I ended up bringing them up a little bit so that the skin
tones didn't look too dark ( Figure 2.28 ).
With curves, you can also make adjustments to very specific tonal
ranges. For example, you may be able to soften some of the clipping in
the sky areas by adjusting a point near the top of the graph. You won't
Fig. 2.28