Graphics Reference
In-Depth Information
Fig. 3.3
Because of the blue clipping, you will never be able to get the blue
highlights all the way up while still getting proper black and gamma lev-
els. Because the blue highlight information is already compromised, we'll
concentrate on getting proper levels in the blacks and gammas. When
you get the gain for red and green to the proper balance, recheck your
black levels; the red channel will be slightly higher than where you left
it originally because of the severe amount of gain needed to get it to the
proper level. Green didn't need much alteration in the highlights, so the
shadows shouldn't have moved. (Remember, all tonal ranges have some
interaction with each other.) Use the blue gain controls to try to get the
midtone area—the sixth chip from the top or bottom—to 50 percent. The
midtone on this image is also where the waveform shows a double line all
the way across the middle of the waveform display (
Figure 3.4
)
.
With gamma, the main swatch of gray that is the background for the
chips should be even across all three channels on the RGB parade wave-
form. As I just pointed out, that gray is indicated on the waveform by the
two parallel lines that go all the way across the cell. The most difficult
channel to correct will be the blue channel, which was the farthest from
correct. Also, due to the clipping, just try to get the gammas and lift cor-
rect for the blue. You'll end up with a pretty good balance except for in
the highlights, where the blue channel is clipped so badly.
The “cheat” for fixing the yellow cast in the highlights is to go back to
the Basic tab and pull the Highlight Sat. control down to 0 or close to it.
In real-world images, this cheat will often work. If you pull the Saturation
control down to 0, you'll see your waveform for the blue channel miracu-
lously seem to “unclip.” But sometimes, this will not work in a real-world
image, because there will be no saturation at all.
Search WWH ::
Custom Search