Begin by clicking the complementary color eye dropper under the Low
Color Wheel. Drag it over the image in the preview window. It is assumed
you already moved a typical frame into the Preview Window. Click it on a dark
area like the man's pants. You'll see the values in the Low color wheel change
from their zero defaults to an angle of 166.0 and and magnitude of 0.128.
Notice the change in the image colors. Where you click is important! Try for a representative color. Avoid absolute blacks and absolute whites if
possible. Aim for something a tad less in each case. Note how the colors in
the darkest part of the image have changed once you click in the Preview
window. If you're not happy with the results, hit the undo button on Vegas'
menu bar and try again. Keep in mind your final results depend on adjusting all three wheels. So until you do the image won't look right yet.
Now repeat using the complementary color eye dropper for High. I
clicked on the man's shirt. Again the values on the Color Wheel and the tones
in the highlight region of the image change. By this time the image is should
be fairly well-corrected, color-wise, because we had both pixels close to black
for lows and to whites for highlights to work with. To adjust midtones,
especially if you have human subjects in the scene you're probably better
off slowly adjusting the Mid Color Wheel manually. The original looked a
little cool, so I warmed it up by moving the midtones on a diagonal towards Y1
and R to add both yellow and red tones to get the hair and skin tone as I
wanted.
Don't be afraid to manually nudge all the wheels after you used the eye
dropper. Or just type in slightly different values in the boxes provided until
you're happy with the hue.
Now look again at the two Histograms. Notice how the bottom one is more
spread out and has lower peaks. While the Color Curve Filter had the most
effect, changing the Gain and Gamma values slightly also can adjust the
position of the peaks on the horizontal axis. This is more of a value
judgment. Much depends on the video you're adjusting, what if anything you
know about the true colors when the video was shot, plus taking into account
the lighting and how the video will be viewed in its final form. Because you are viewing this tutorial at a web page on a computer monitor, it looks different than it would on an external monitor connected via firewire; this is important to remember when you're making these kind of adjustments.
Unless you plan to only view your video on your computer, be sure to use an external monitor, or all of the work spent making adjustments was for nothing.
Final Tips: For best results you need to shift your focus from
the view on the external monitor to the Histogram and Luminance waveform which
is the right most chart in the above screen shot. Note that it has a scale of
120 to minus 20. Look closely at the before and after views. In the original
the waveform is concentrated mostly between the range of 20 and 60. If you
look closely at the after waveform you'll see a change in the pattern with
more pixels in a higher range. By carefully making minor adjustments
alternating between Gamma and Gain you can center the waveform on the
horizontal in the bottom Histogram while watching the vertical shift in the
upper wave form. Just keep the Gamma and Gain settings so that no part of the
waveform gets above 110; a slightly lower value, like 100, is probably better for most
videos. You can also use the offset slider to add or subtract the the
luminance. This control is super-sensitive, and a little movement goes a long way. Only rarely would you want to go much beyond +/-20. Also , remember that the Gain and Offset work interactively.
