Primary Color Correction: Color Control Primer - The Art and Technique of Digital Color Correction - page 97

blacks, and the shadows in the waveform also indicate that there is prob-
ably clipping in the blacks as well, but the image is very well exposed. You
can see that in the waveform, but the histogram gives no sense that the
image is well exposed.
The other problem with histograms is that there's not a lot of variety
in the way that they can be displayed in most software. You can't zoom in
on portions of the waveform to get a better view like you can with wave-
form monitors and vectorscopes. They are also rarely calibrated with any
sort of indication about specific levels or numbers of pixels. Even if they
had that kind of information, it still wouldn't help much. Why would you
care if there were 6000 pixels that were a certain shade of middle gray?
In defense of the histogram, many people who do retouching like to
use the histogram to set blacks and highlights because it allows them to
see when there's room to either pull the blacks down or the highlights up.
As soon as they start to see clipping occur (a sharp spike at either end),
then they can either stop to retain detail or continue pushing the contrast,
knowing that they're clipping their image. For me, and most experienced
colorists, you get the same amount of information from a waveform mon-
itor, with the added bonus that you know the specific area (horizontally)
that the clipping occurs. This gives you some guidance when you're try-
ing to assimilate what the scope is telling you with what the video moni-
tor is telling you.
You can also get a sense of color balance by looking at the histogram to
see whether the shadow end or highlight end of one of the color channels
is higher or lower than one of the other channels.
For a quick tutorial, try to use the histogram in Color to balance the
shot of the Field Museum. I tried doing it with the Final Cut Pro hue offset
wheels with a little success, and I got even closer using the blacks, mids,
and whites sliders. In any room in Color, you can switch one of the scopes
to histogram view by right-clicking on the scope that you want to change
to a Histogram and choosing “Histogram” from the contextual pulldown
menu that appears where your mouse was positioned ( Figure 3.33 ) .
You can view the histograms with all three channels at once using
“RGB” ( Figure 3.34 ) or you can see larger images of each of the color
channels individually using the R, G, or B buttons at the top left corner
of the histogram. You can also view the luminance of the image using the
“Luma” button.
Use the three “lift” sliders for each color in the Advanced Tab to bring
the shadow end of the histogram down so that each of the spikes on the
left side of the histogram were even with each other. Notice that the large
“mounds” to the left—black—are one above the other. See Figure 3.35 .
Then adjust the three gain controls so that the tall “skyscraper”
at the right side of each color channel lines up one above the other
( Figure 3.36 ).