Adobe After Effects - Manual (Page 89)

Note:
Drop Frame versus Non-Drop Frame
Frames
Feet + Frames
To the top
Timecode
Note:
Frames
Feet + Frames
Frame Count
Timecode Conversion
Start at 0
Start at 1
Note:
To the top
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.
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.
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 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.
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.
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.
Options for time-display units in After Effects CS5.5 and later
Displays time as timecode in the time rulers of the Timeline, Layer and Footage panels, using either Use Media Source (source
timecode) or starting at 00:00:00:00. Select the Timecode option to use timecode instead of Frames. Note that there are no options for choosing
frame rate or drop-frame / non-drop-frame, as source timecode is detected and used instead.
In After Effects CS5.5 and later, timecode is no longer a global setting for projects. You may have both drop-frame and non-drop-frame
timecode in any composition within a project.
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. To use Frames, select Frames and deselect Feet + Frames.
Displays the number of feet of film, plus frames for fractional feet, for 16mm or 35mm film. To use Feet + Frames, select Frames
and select Feet + Frames.
Determines the starting number for the time display style for Frames.
Timecode value of the item is used for the starting number (if the item has source timecode). If there is no
timecode value, counting begins with zero. Timecode Conversion causes After Effects to behave as it has in previous versions, where the
frame count and the timecode count of all assets are mathematically equivalent.
The counting for frames begins at zero.
The counting for frames begins at one.
The new options of “Start at 0” and “Start at 1” allow you to specify different frame counting schemes between the “Frames” and
“Timecode.” For example, you might choose to honor the source timecode of footage items, but count frames beginning at zero or one.
Source timecode (CS5.5 and later)
85