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380 Chapter 19: Video Post-Production
Inter face
Radial—Radial gradients work from the center
point to the outer edge of a Lens Effects feature,
changing color or brightness in a straight line from
left to right as you scan the gradient bar. The left
edge of the g radient is alig ned w ith the center of
the effect and the rig ht edge is aligned with the
outer edge of the effect.
Scheme of a radial gradient
Circular—Changes colors in a circular manner,
working clockwise around a Lens Effects feature. If
you mark North, E ast, South, and West on a c ircle,
these points represent the 0%, 25%, 50%, and 75%
marks of the gr adient.
Each parameter panel in Flare, Glow, and
Highlight that utilizes gradients contain five
gradient controls. The five controls are:
Scheme of a circular gradient
Color (Ra dial and Circular)—Defines the colors used
(page 3–381) foraneffect.Thisisbasedonthe
RGB color system, but can also be set with HSV.
Withineachsetofgradientcontrols,thereisa
Radial and Circular Color gradient. Radial Color
works with Circular Color to produce the overall
color for the Lens Effects element.
Transparency (R adial and Circular)—Va r i e s t h e
visibility of parts of the effect. The transparency
gradients only m a ke use of brightness (or
luminance) values, which are essentially grayscale
values. This black-to-white ramp of values
pro vides you with 256 levels of transparency
foryoureffects. JustliketheColorgradients,
both Transparency gradients are tied together
to generate the overall visibility of effect. See
Gradient Options (page 3–378).
Size—Varies the s ize of specific parts of the Lens
Effect.Mostsizegradientsareusedtoaffectthe
radius of a lens flare part, such as a glow. Like
transparency gradients, only the brightness values
are used to provide you with 25 6 different s izes.
The Radial Size gradient, for exa mple, works both
like a Radial and Circular gradient. This gradient
is applied in a clockwise fashion, s tarting at 12
o’clock. The values in the gradient are applied
from the center of the effect toward the outer edge,