Options for time-display units, Online resources about timecode – Adobe After Effects CS4 User Manual
Page 59
53
USING AFTER EFFECTS CS4
Projects and compositions
Last updated 12/21/2009
Change time-display units
•
To cycle through Timecode Base, Frames, and Feet + Frames, Ctrl-click (Windows) or Command-click (Mac OS)
the current-time display. The current-time display is in the upper-left corner of the Timeline panel and at the
bottom of the Layer, Composition, and Footage panels. (See “
•
To change time display units, choose File
> Project Settings, and choose from the options in the Display Style
section.
Options for time-display units
Timecode Base
Displays time as timecode, using the frame rate that you specify as the timecode base. Auto uses the
rounded frame rate of the footage item or composition. If an item doesn’t have timecode (such as an audio file), After
Effects uses a default value (30 fps for English, Japanese, and Korean versions of After Effects, or 25 fps for French,
German, Spanish, and Italian versions) or the last non-auto value you specified in the Project Settings dialog box. You
can also specify that After Effects use a specific frame rate.
Note: You can specify specific frame rates for display in the Timecode Base menu; however, in most cases, you should leave
the timecode base set to Auto.
Drop Frame versus Non-Drop Frame
Two of the more commonly used combinations of time display settings are 30 fps
drop-frame timecode and 30 fps non-drop-frame timecode. When the frame rate is a non-integer number—as is the
case with the NTSC frame rate of 29.97 frames per second—a compromise of one sort or another must be made in
displaying time. Either the time display can accurately show clock time (after one hour, the time display shows
1:00:00:00) or the time display can be continuously numbered (frame n is always followed by frame n + 1, modulo the
number of frames per second). Drop-frame timecode does the former; non-drop-frame timecode does the latter. In
the case of NTSC 30 fps drop-frame timecode, two frame numbers are skipped for each minute, except for every tenth
minute. Drop-frame timecode is conventionally indicated by separating the time units with semicolons. The most
common case for which drop-frame versus non-drop-frame timecode is relevant is 29.97 fps NTSC, but it also applies
to 23.976 fps (which After Effects treats as non-drop-frame timecode) and 59.94 fps.
Timecode for 59.94 fps compositions and footage items matches that in Adobe Premiere Pro: When the timecode base
is 30 fps, each timecode value repeats twice. When the timecode base is 60 fps drop-frame, frame numbers 0, 1, 2, and
3 are dropped in the same places as where 0 and 1 are dropped for drop-frame timecode with a timecode base of 30 fps.
Feet + Frames
Displays number of feet of film, plus frames for fractional feet, for 16mm or 35mm film. Numbering
starts at the frame number that you specify with the Start Numbering Frames At value.
Frames
Displays frame number instead of time. Use this setting for convenience when doing work that you are
integrating with a frame-based application or format, like Flash or SWF.
Online resources about timecode
Trish and Chris Meyer provide an article on the
drop-frame and non-drop-frame timecode.