User Guide

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ADOBE AFTER EFFECTS 5.0
User Guide
• The maximum resolution you can import or export is limited by the amount of physical
RAM available to After Effects. When working with large frame sizes, minimize the RAM
used by the system or other software running on your computer, but be sure to leave at
least 4 MB unused to handle system software requirements for additional RAM.
• The following formula helps you determine the amount of RAM you need based on the
footage: Image Width in Pixels x Image Height in Pixels x 4 Bytes of Memory for 32 bits-
per-pixel (bpp) or 8 Bytes of Memory for 64 bpp. For example, a 30,000-x-30,000-pixel
image requires 3.5 GB of RAM to import and display each frame. However, a 30,000-x-
486-pixel image requires only 60 MB of RAM. Memory requirements for 16 bits-per-
channel (bpc) project color depth are approximately double those for 8 bpc.
Changing the default duration of still images
When you add a still image to a composition, its default duration is the duration of the
composition. You can manually trim the duration of a still image and change the default
duration of still footage in the Import Preferences dialog box. See “Understanding
trimming” on page 139.
To change the default duration of still footage:
1 Choose Edit > Preferences > Import.
2 Under Still Footage, do one of the following, and then click OK:
• Select Length of Composition: sets the same duration for the still image as the compo-
sition into which it is placed.
• Type numbers in the text box for the duration you want to use.
Specifying interpretation rules
The Interpretation Rules.txt file describes how After Effects interprets field order, alpha
channel, frame rate, and pixel aspect ratio when importing footage. You can customize
this file in any text editor and add or delete entries, to save time. When you import, After
Effects reads the file and follows any applicable rules, as long as Interpretation Rules.txt is
stored in the same folder as the After Effects application. You can always override these
interpretations after importing. For more information about specifying interpretation
rules, see online Help.
UG.book Page 67 Wednesday, February 21, 2001 12:05 PM