Apple Final Cut Pro 5 - Manual (Page 85)

84 Part II Learning About the Final Cut Pro Interface
 RGB, Alpha, or Alpha+RGB: When you’re compositing, it can sometimes be handy to
have a quick look at the alpha channel of your clip. The alpha channel defines areas
of transparency, and can change if various filters are applied. Viewing your sequence
with the Alpha or Alpha+RGB option selected shows you exactly which areas of your
image have transparency. Additional controls are available for viewing the individual
Red, Green, and Blue channels in the View menu.
Important: If the image display area in the Viewer is all black or all white, it may be
because the Canvas is set to view only the alpha channel instead of the RGB
channels. Try changing the channel view to RGB to solve this problem.
 Black, White, Checkerboard: When working with clips that have an alpha channel, you
can choose different backgrounds to make it easier to see which areas of your
picture are transparent. For example, translucent clips or generated text may be
more visible if you choose a background that emphasizes them, such as
Checkerboard 1 or 2. You can also view Red, Green, and Blue background colors
using the View menu.
None of these view options affect either rendered output or material sent to tape. They
only affect display in Final Cut Pro.
Playhead Sync Pop-Up Menu
You can lock the Viewer playhead to the Canvas/Timeline playhead so that they move
together while scrubbing through clips.
Note: This menu also appears in the Canvas, and the options are the same.
Playhead Sync pop-up
menu in the Viewer