Classroom in a book

5
Set the zoom of the Program Monitor back to Fit when you are done adjusting 
the Four-Point Garbage Matte control points.
6
Expand the Motion field, and adjust the Size, Position, and Rotation fields so 
that the face appears in the upper-right corner, as shown here on the right. 
Consider adding a Bevel Alpha effect to make the image stand out from the 
background.

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LESSON 15 Exploring Compositing Techniques
Creating a split-screen effect
You can use garbage mattes to create split-screen effects. The most frequent 
application is simply to layer two clips, apply the Four-Point Garbage Matte effect to 
each, and move the vertices to create two side-by-side rectangles. You can also layer 
more clips and use the Eight- and Sixteen-Point Garbage Matte effects to create all 
sorts of shapes.
The one little gotcha is that the garbage matte effects reveal part of a clip—they 
don’t shrink the clip to fit it in the borders of the garbage matte, as happens when 
you use Motion to make PIPs. So, plan your shots accordingly. If you want to put 
more of the scene within the garbage matte’s borders, use Motion or some other 
effect to accomplish that.
You can achieve a cool effect by locking down your camcorder on a tripod (ensur-
ing the lighting, focus, and exposure settings don’t change for the duration of the 
shoot) and having an actor do a scene on one side of a set and then play another 
role on the other side of the set. You can use a garbage matte on one of the scenes 
to have the actor appear on both sides of the set at once.
This takes some planning. The actor shouldn’t cross the line that divides the set 
in two (though you can keyframe the garbage matte box edges to accommodate 
some overlap), and there can’t be any movement in the vicinity of the scene’s 
dividing line.