Adobe 25520388 - Premiere Pro - PC Using Manual page 384

USING ADOBE PREMIERE PRO
Effects and transitions
Reverses the transparency and opaque areas of the clip.
Invert Alpha
Applies the effect only to a masked area.
Mask Only
Blue Screen Key effect (Windows only)
The Blue Screen Key effect creates transparency from true chroma blue. Use this key to key out well-lit blue screens
when creating composites.
The following Blue Screen Key effect settings are adjusted in the Effect Controls panel:
Sets the levels of blue that determines transparent areas in a clip. Dragging the slider to the left increases
Threshold
the amount of transparency. Use the Mask Only option to view black (transparent) areas as you drag the Threshold
slider.
Sets the opacity of nontransparent areas specified by the Threshold setting. Dragging the Cutoff slider to the
Cutoff
right increases the opacity. Use the Mask Only option to view white (opaque) areas as you drag the Cutoff slider.
Specifies the amount of anti-aliasing (softening) applied to the boundary between transparent and opaque
Smoothing
regions. Choose None to produce sharp edges, with no anti-aliasing. This option is useful when you want to preserve
sharp lines, such as those in titles. Choose Low or High to produce different amounts of smoothing.
Displays only the clip's alpha channel. Black represents transparent areas, white represents opaque areas,
Mask Only
and gray represents partially transparent areas.
Subject is photographed against blue background (left). Blue Screen Key effect is applied (right) to superimpose subject over underlying track.
For more information about using blue screen and green screen effects, see the
Chroma Key effect (Windows only)
The Chroma Key effect keys out all image pixels that are similar to a specified key color. When you key out a color
value in a clip, that color or range of colors becomes transparent for the entire clip. Control the range of transparent
colors by adjusting the tolerance level. You can also feather the edges of the transparent area to create a smooth
transition between the transparent and opaque areas.
A
Chroma Key effect
A. Original image B. Blue color keyed out C. Image on second track D. Final composite image
The following Chroma Key effect settings are adjusted in the Effect Controls panel:
Broadens or reduces the range of the target color that will be made transparent. Higher values increase the
Similarity
range.
C
B
Last updated 1/16/2012
Metacafe website.
D
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