Classroom in a book

Color keying a green-screen 
shot with Ultra Key
Keying effects use various methods to make portions of a clip transparent. To get a 
quick overview, choose Video Effects > Keying in the Effects panel. You’ll see many 
effects. With the exception of Alpha Adjust (the clip-based Opacity video effect), 
they fall into three basic categories:

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ADOBE PREMIERE PRO CS5 CLASSROOM IN A BOOK
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Color/chroma
: Blue Screen (Windows only), Chroma (Windows only), Color, 
Non-Red, RGB Difference (Windows only), and Ultra Key
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Luminance
: Luma, Multiply (Windows only), and Screen (Windows only)
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Matte
: Difference, Garbage, Image, Remove, and Track
Color keys and chroma keys all work in basically the same way: You select a color 
for them to make transparent and then apply a few other parameters (basically 
adjusting the width of that color selection). Luminance keys look for dark or light 
areas in a clip and make them transparent or opaque.
Rather than relying on color or brightness to exclude areas, mattes allow you to man-
ually exclude regions in the frame by dragging a box around them, like the Garbage 
matte, or by using a graphic. We’ll spend more time on matte keys later in the lesson.
Using the Ultra Key effect
Now you’ll use the Ultra Key effect, which is a powerful new feature in CS5.
1
Load Lesson 15-3.prproj.
2
Scrub the Timeline to see the background you are using for the green-screen clip.
3
Drag greenscreen.mp4 to Video 2. Play the Timeline now to see the hero talking 
in front of a green screen that obscures the clip on Video 1. Don’t adjust your 
speakers as this track has no audio.
4
In the Program Monitor, choose Fit for the zoom magnification level. It’s 
important to be able to see the entire frame, because most problems with 
keying occur around the edges.