Apple Final Cut Pro 6 - Manual (Page 1195)

410 Part II Effects
To manually change the frame rate of a layered Photoshop sequence:
1 Select the layered Photoshop sequence in the Browser, then choose Sequence > Settings.
2 Choose a frame rate from the Editing Timebase pop-up menu, then click OK.
If affiliate copies of this layered Photoshop sequence have already been edited into
other sequences, Final Cut Pro does not allow you to change the sequence frame rate.
In this case, you can manually create a duplicate master clip of this sequence.
To create a duplicate master clip of a layered Photoshop sequence:
1 Select a layered Photoshop sequence in the Browser.
2 Choose Modify > Duplicate as New Master Clip.
A new master clip is created whose frame rate you can modify for nesting into
other sequences.
Using Video and Graphics Clips with Alpha Channels
Ordinary video clips have three channels of information for red, green, and blue. An
alpha channel is an additional channel that defines areas of transparency in the clip or
image. If you import a QuickTime movie or a still image from another application, or a
file that’s been created by a 3D animation program, it may have an alpha channel in
addition to its color channels. An alpha channel is a grayscale channel where levels of
white and black determine varying degrees of transparency applied to the color
channels during compositing.
When you import a QuickTime movie or an image file, its alpha channel is recognized
immediately. When you edit the movie or image file into a sequence, Final Cut Pro uses
the alpha channel to composite the movie or image file against any clips appearing in
video tracks below it.
Note: Alpha channels work the same in video and still-image media files.
Foreground
graphic
Alpha
channel
Background
graphic
Final
composite