Apple Final Cut Pro 7 - Manual (Page 1217)

There are several channel viewing options in the View menu and the View pop-up menu
in the Viewer.
• RGB: This is the default color option; it shows the three color channels that make up
the actual video image.
• Alpha: This option represents the alpha channel as black against white, where absolute
black represents 100 percent transparency, levels of gray represent varying degrees of
transparency, and absolute white represents nontransparent areas of the picture.
• Alpha+RGB: This option lets you see a representation of the alpha channel overlaid on
top of the RGB channels that constitute the actual image of the video clip. The alpha
channel is overlaid in red, with solid red representing nontransparent areas.
The RGB and Alpha options in the View menu are most effective when used with different
backgrounds, described in
“Choosing a Background.”
1217 Chapter 71 Compositing and Layering