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.
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Adobe Premiere Pro Help Superimposing and Compositing
Using Help | Contents | Index Back 228
Blend
Blends the clip you are keying out with the underlying clip. Higher values blend
more of the clip.
Threshold
Controls the amount of shadows in the range of color you keyed out. Higher
values retain more shadows.
Cutoff
Darkens or lightens shadows. Drag to the right to darken shadows, but do not
drag beyond the Threshold slider; doing so inverts gray and transparent pixels.
Smoothing
Specifies the amount of anti-aliasing that Adobe Premiere Pro applies to the
boundary between transparent and opaque regions. Anti-aliasing blends pixels to
produce softer, smoother edges. Choose None to produce sharp edges, with no
antialiasing.
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.
Mask Only
Displays only the clip’s alpha channel, as modified by the key settings.
Using the RGB Difference key
The RGB Difference key is a simpler version of the Chroma key. You can select a range
of color, but you cannot blend the image or adjust transparency in grays. Use the RGB
Difference key for a scene that is brightly lit and contains no shadows, or for rough cuts
that don’t require fine adjustments. 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 RGB Difference key settings as necessary:
Similarity
Broadens or reduces the range of color that will be made transparent. Higher
values increase the range.
Smoothing
Specifies the amount of anti-aliasing (softening) that Adobe Premiere Pro
applies to the boundary between transparent and opaque regions. Choose None to
produce sharp edges, with no anti-aliasing. This option is useful when you want to
