Adobe After Effects CS4 - Manual (Page 41)

35 USING AFTER EFFECTS CS4
Workflows, planning, and setup
Last updated 12/21/2009
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 “
Composition
settings ” on page 58.
If you’ll be rendering and exporting a composition to more than one media format, always match the pixel dimensions
for your composition to the largest pixel dimensions used for your output. Later, you can use output modules in the
Render Queue panel to encode and export a separate version of the composition for each format. See “ Output modules
and output module settings ” on page 700.
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 and storage ” on page 632.
If your source footage files are on a slow disk drive (or across a slow network connection), then performance will be
poor. When possible, keep the source footage files for your project on a fast local disk drive. Ideally, you’ll have three
drives: one for source footage files, one from which the application runs, and one for rendered output.
For more information, see “ Improve performance ” on page 637.
Planning for playback on computer monitors and mobile devices
When you create a movie for playback on a personal computer—whether downloaded from the Web or played from
a CD-ROM—specify composition settings, render settings, and output module settings that keep file size low.
Consider that a movie with a high data rate may not play well from an older CD-ROM drive that cannot read data from
the disc fast enough. Similarly, a large movie may take a long time to download over a dial-up network connection.
When rendering your final movie, choose a file type and encoder appropriate for the final media. The corresponding
decoder must be available on the system used by your intended audience; otherwise they will not be able to play the
movie. Common codecs (encoders/decoders) include the codecs installed with media players such as Flash Player,
Windows Media Player, and QuickTime Player.
Aharon Rabinowitz provides an article on the Creative COW website about planning your project with the final
delivery specifications in mind.
Trish and Chris Meyer provide an article on the Artbeats website that describes some of the considerations for creating
video for the Web.
Mobile devices
Many of the considerations for creating movies for playback on mobile devices, such as mobile phones and the Apple
iPod, are similar to the considerations for creating movies for playback on personal computers—but the limitations
are even more extreme. Because the amount of storage (disk space) and processor power are less for mobile phones
than for personal computers, file size and data rate for movies must be even more tightly controlled.
Screen dimensions, video frame rates, and color gamuts vary greatly from one mobile device to another. Adobe Device
Central contains device profiles that provide information about these characteristics. You can create a set of After
Effects compositions tailored for a selected set of devices by using the File > New Document In > After Effects
command in Adobe Device Central. (See “
Create compositions for playback on mobile devices ” on page 56.)