Adobe AFTER EFFECTS CS3 PROFESSIONAL User Manual page 32

If possible, use uncompressed footage: less compression means better results for many operations, such as keying and
motion tracking. Certain kinds of compression—such as that used in DV encoding—are especially bad for color
keying, because they discard the subtle differences in color that you depend on for good bluescreen or greenscreen
keying. It's often best to wait until the final rendering phase to use compression. See "Keying overview" on page 268.
If possible, use footage with a frame rate at least that of your output, so that After Effects doesn't have to use frame
blending or similar methods to fill in missing frames. See "Change frame rate" on page 63.
The kind of work that you'll be doing in After Effects and the kind of output movie that you want to create can even
influence how you shoot and acquire your footage. For example, if you know that you want to animate using motion
tracking, you should consider shooting your scene in a manner that optimizes for motion tracking—for example,
attaching a small, brightly colored ball to the object that you intend to track. See "Motion tracking workflow" on
page 335.
Project settings
Project settings fall into three basic categories: how time is displayed in the project, how color data is treated in the
project, and what sampling rate to use for audio. Of these, the color settings are the ones that you need to think about
before you do much work in your project, because they determine how color data is interpreted as you import
footage files, how color calculations are performed as you work, and how color data is converted for final output. See
"Color management" on page 240 and "Change time display units" on page 135.
If you enable color management for your project, the colors that you see are the same colors that your audience will
see when they view the movie that you create.
Note: Click the color depth indicator at the bottom of the Project panel to open the Project Settings dialog box. Alt-click
(Windows) or Option-click (Mac OS) to cycle through color bit depths: 8 bpc, 16 bpc, and 32 bpc. See "Set the color depth"
on page 234.
Composition settings
After you prepare and import footage items, you use these footage items to create layers in a composition, where you
animate and apply effects. When you create a composition, specify composition settings such as resolution, frame
size, and pixel aspect ratio for your final rendered output. Although you can change composition settings at any time,
it's best to set them correctly as you create each new composition to avoid unexpected results in your final rendered
output. For example, the composition frame size should be the image size in the playback medium. See "Work with
composition settings" on page 114.
If you'll be rendering a composition to more than one media format, always match the resolution setting for your
composition to the highest resolution setting used for your output. Later, you can use output modules in the Render
Queue panel to render a separate version of the composition for each format. See "Work with output module settings"
on page 594.
Performance, memory, and storage considerations
If you work with large compositions, make sure that you configure After Effects and your computer to maximize
performance. Complex compositions can require a large amount of memory to render, and the rendered movies can
take a large amount of disk space to store. Before you attempt to render a three-hour movie, make sure that you have
the disk space available to store it. See "Memory, storage, and performance" on page 34.
AFTER EFFECTS CS3 26
User Guide