Apple Final Cut Pro 7 - Manual (Page 1926)

Error between
timecode number and
real time
Time passed
(29.97 fps) Timecode labels
(30 fps)
Frame count
0.001 minutes
0.06 seconds
1.8 frames
=1800/29.97 of a
second
= 60.06 seconds
= 1.001 minutes
1800/30 of a second
= 60 seconds
= 1 minute
1800
0.01 minutes
0.6 seconds
17.9 frames
= 18,000/29.97 of
second
= 600.6 seconds
= 10.01 minutes
= 18,000/30 of a second
= 600 seconds
= 10 minutes
18,000
0.001 hours
3.6 seconds
107.89 frames
=108,000/29.97 of a
second
= 3603.6 seconds
= 1.001 hours
= 108,000/30 of a
second
= 3600 seconds
= 1 hour
108,000
If you edit an hour-long program on NTSC video, the 30 fps timecode indicates that the
last frame of the program is frame 108,000, labeled as timecode 01:00:00:00 (non-drop
frame). However, the table above shows that because the video actually runs at 29.97 fps
(each frame is slightly longer than if it were running at 30 fps), 1 hour has actually passed
at frame 107,892 (3.6 seconds earlier than the 30 fps timecode shows). What editors
wanted, particularly in television environments, was a method of frame addressing that
accurately reflected how much time had passed.
Drop frame timecode was invented to compensate for the discrepancy between 29.97
and 30 fps. Every minute except each tenth minute, two timecode numbers are dropped
from the timecode count. This drop frame mode of 30 fps timecode remains accurate
compared to the actual time passed, with a strange side effect that two numbers each
minute vanish from the count.
The Difference Between Frame Rate and Timecode
The frame rate of your film or video describes how rapidly frames are photographed or
played back. It refers to the physical speed of image capture and playback. Timecode is
merely a method of labeling frames with unique identifiers to easily find them again later.
It is a convenient way of giving each frame a name that can be referred to later without
having to verbally describe and visually search for it. Even though frame rate and timecode
are independent, people commonly confuse the two, which can lead to frustrating
problems in post-production. Before you start a project, be certain that you understand
the difference between these two terms.
1926 Appendix C Frame Rate and Timecode