User Guide

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ADOBE AFTER EFFECTS 5.0
User Guide
• Create a new composition at the smaller dimensions, and nest the large composition
inside it. For example, if you create a 640 x 480 composition, you can place it in a 320 x
240 composition. Scale the composition to fit the new smaller composition size, and
collapse transformations by choosing Layer > Switches > Collapse. The resulting compo-
sition rendered at full resolution and best quality will have excellent image quality, better
than if you had rendered using a reduced resolution.
• Stretch the movie. This method produces the highest quality reduced-size movie but is
slower than nesting. For example, if you create a 640 x 480 composition and render it at
full resolution, you can set the stretch value in Output Module Settings to 50% to create a
320 x 240 movie. For a composition rendered at full resolution, the image quality is
excellent when the Stretch Quality is set to High.
Note: Do not use stretching to change the vertical dimensions of a movie when field rendering
is on. Stretching vertically mixes the field order, which distorts motion. Use either cropping or
composition nesting if you need to vertically resize a field-rendered movie.
• Crop the movie. This method is ideal for reducing the size of a movie by a few pixels. Use
the Crop options in the Output Module Settings dialog box. Remember that cropping cuts
off part of the movie, so objects centered in the composition may not appear centered
unless the movie is cropped evenly on opposite edges.
Note: Cropping an odd number of pixels from the top of a field-rendered movie reverses the
field order. For example, if you crop one row of pixels from the top of a movie with Upper Field
First field rendering, the field-rendering order then becomes Lower Field First. Remember that
if you crop pixels from the top of the movie, you need to add to the bottom row of the movie to
maintain the original size. If you are willing to lose one scan line, this gives you a way to
output two movies from one render, each with a different field order. See “Using interlaced
video in After Effects” on page 85 and “Field-rendering considerations” on page 360.
• Render the movie at a reduced resolution. This is the fastest method to create
reduced-size movies. For example, if you create a 640 x 480 composition, you can set
the composition resolution to one half, reducing the size of the rendered composition
to 320 x 240. You can then create movies or images at this size. Note that the reduced
resolution reduces the sharpness of the image and is best used for creating preview or
draft movies.
Note: When rendering at reduced resolution, set the quality of the composition to Draft.
Rendering at Best quality while reducing resolution does not produce a clean image and takes
longer to render than rendering at Draft quality.
UG.book Page 385 Wednesday, February 21, 2001 12:05 PM