Apple Final Cut Pro 5 - Manual (Page 1153)

366 Part II Project Interchange
 Darken: Compares the color values for each pixel of the selected clip with those of
the clip beneath it in the Timeline, and selects the darker of the two. In this example,
the lightest parts of the layered image of sheet music become transparent, while the
darker parts darken the background image of the singer.
 Lighten: Compares the color values for each pixel of the selected clip with those of
the clip beneath it in the Timeline, and selects the lighter of the two. In this example,
the darkest parts of the layered image become transparent, while the lighter parts
lighten the background image of the singer.
 Travel Matte - Alpha or Luma: Applies a matte to the selected clip, which is an effect
that uses information in one layer of video to affect another layer. In this case, the
selected clip uses information from the clip immediately beneath it in the Timeline.
The matte makes the area outside the matte transparent so the second layer
underneath the clip is displayed.
Travel mattes always involve three tracks. The foreground clip is on the upper track.
The matte track goes on the middle track, and the background clip (or clips, if
transparent) goes on the bottommost track. The Travel Matte composite mode is
then applied to the foreground clip on top of this stack. Travel mattes can be
enabled in two ways:
 Alpha: Ignores RGB values, using the alpha channel of the matte layer to create
transparency information for the selected clip.
 Luma: Averages the RGB values of the matte layer to gray. The resulting grayscale
image is used to create transparency information for the selected clip, with white
equal to 100 percent transparent and black equal to 100 percent solid.