Using Help
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227
Adobe Premiere Pro Help
Superimposing and Compositing
Using Help
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Contents
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Index
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227
Using keys
You can apply
keys
that define transparent areas based on values such as color or
brightness that exist within a clip. Use color-based keys for knocking out a background,
brightness keys for adding texture or special effects, alpha channel keys to modify a clip’s
alpha channel, and matte keys for adding traveling mattes or applying other clips as
mattes. (See
“Using matte keys” on page 230
.)
To apply a key to a clip:
1
In the Effects window, expand the Video Effects bin and then the Keying bin.
2
Drag a key to a clip in the Timeline window.
Dragging a key from the Effects window to a clip in the Timeline window
3
In the Video Effects section of the Effect Controls window, click the triangle next to the
key effect name to expand it and view options.
4
Adjust the key’s options.
To more effectively evaluate the settings of a key effect, choose New Reference
Monitor from the Monitor window menu in the Program view, and then choose Alpha
from the reference monitor’s window menu. This lets you view the clip’s composite view
and the clip’s alpha channel simultaneously.
Using the Chroma key
Use the Chroma key to select a color or a range of colors in the clip to be transparent. You
can use this key for a scene shot against a screen that contains a range of one color, such
as a shadowy blue screen. Select a key color by clicking the Color swatch or by dragging
the eyedropper to a color in the Monitor window. Release the mouse button only when
the eyedropper is over the color you want, as indicated by the swatch next to the
eyedropper.
Adjust the following Chroma key settings as necessary:
Similarity
Broadens or reduces the range of color that will be made transparent. Higher
values increase the range.
