Apple Final Cut Express 4 - Manual (Page 851)

Chapter 53 Keying, Mattes, and Masks 851
IX
7 Depending on how the edges of your foreground subject look, you may want to make
adjustments using the Edge Thin slider. The Edge Thin slider allows you to shrink the
alpha channel created by the Chroma Keyer to begin to eliminate the light fringing
that remains around the edges of the foreground subject.
8 An optional step at this point is to use the Softening slider to blur the edges of the
foreground subject. This is especially helpful if the edges of your foreground subject
look rough because of compression artifacts that appear as blocky edges around your
foreground subject. Don’t overdo this adjustment, as you could start to lose details in
the subject that you’re trying to preserve.
Before adjusting the
Edge Thin slider
After dragging the
Edge Thin slider to
the right
Before adjusting the
Softening slider After dragging the Softening slider
slightly to the right