5

• Black, White: Click the disclosure triangle in the Spill Contrast row to reveal sliders for
the Black and White point parameters. These sliders, which mirror the settings of the
Spill Contrast handles described above, allow you to keyframe the Black point and
White point parameters (via the Add Keyframe button to the right of each slider).
• Tint: Use this slider to restore the natural color of the keyed foreground subject. Because
the Spill Suppression controls eliminate blue or green spill by desaturating subtle blue
or green fringing and reflection on the subject, the Tint slider lets you add hues to
restore the natural color of the subject. Overdoing this parameter results in over-tinting
the subject with the complementary color of the hue being suppressed—magenta if
green, and orange if blue.
• Saturation: Use this slider to alter the range of hues introduced by the Tint slider (when
the Tint slider is used at moderate levels).
Light Wrap: Click the disclosure triangle in the Light Wrap row to reveal controls for
blending color and lightness values from the background layer of your composite with
the keyed foreground layer. Using these controls, you can simulate the interaction of
environmental lighting with the keyed subject, making it appear as if background light
wraps around the edges of a subject. In the following image on the right, with Light Wrap
applied, environmental lighting from the orange sky background layer appears on the
edges of the candle and on the top of the woman’s dress.
Without Light Wrap With Light Wrap
In Motion, the Light Wrap operation blends light and dark values from the background
with the edges of the keyed foreground subject, and can be used to create color mixing
effects around the edges of the solid part of a key to better marry the background and
foreground layers of your keyed composite.
Light Wrap is the last operation in the image-processing pipeline. In other words, the
light-wrap effect is added after every other image operation is processed, including filters,
lights and shading, and other composited effects. As a result, Light Wrap properly accounts
for any other visual effect that might alter the look of the object it is applied to, yielding
the most desirable result.
648 Chapter 13 Keying