Apple Color 1.0 - Manual (Page 218)

218 Chapter 10 Secondaries
Each Qualifier Explained
 H (hue): Defines the range of colors that contribute to the key. Using Hue by itself to
define a keyed matte can yield similar results to using the Hue, Sat, and Lum
secondary curves. Because the visible spectrum is represented by a wrap-around
gradient, the H handles are the only ones that wrap around the ends of this control,
allowing you to select a complete range of blue to green, when necessary.
 S (saturation): Defines the range of saturation that contributes to the key. Using
saturation by itself to define a keyed matte can be effective for manually limiting
oversaturated colors. Using saturation and hue, but excluding lightness, lets you
manually limit specific colors throughout the image.
 L (lightness): Defines the range of lightness that contributes to the key. Using
lightness by itself to define a keyed matte is an extremely powerful technique that
lets you quickly isolate regions of the highlights, midtones, or shadows to perform
specific adjustments such as increasing or reducing the specific lightness of shadows,
or manipulating the color within highlights.
 Reset button: Resets all three qualifiers to the default state, which is an all-inclusive
selection.
The Color Swatches
A set of six swatches underneath the HSL qualifiers let you automatically set the Hue
qualifier to a narrow range that’s centered on one of the primary red, green, and blue,
and secondary cyan, magenta, and yellow colors.
The swatches can be useful when you need to quickly make a Hue selection for a
feature in the image that corresponds to one of these colors. When you choose one of
these swatches, the Saturation and Lightness controls remain completely unaffected.
To adjust the Hue qualifier using one of the color swatches:
m Shift-click any of the swatches.
The Hue qualifier resets itself to select the corresponding range of color.
Key Blur
The Key Blur parameter lets you apply a uniform blur to the keyed matte in order to
soften it. This can go a long way toward making an otherwise noisy or hard-to-pull key
usable. This parameter defaults to 0, with a maximum possible value of 8.