Appendix 1

When Shooting on Film
everything that was done during telecine, including key code information from the negative as well
as video and audio time codes. (For more information on syncing in telecine, see Chapter 3 on audio
capture and syncing.)
The footage undergoes several changes during this process besides the obvious change from fi lm to
video. The colors are manipulated, sound can be added, the frame rate is changed and the playback
speed is slowed down by .1 percent.
The Conversion of 24 FPS Film to 29.97 FPS Video with 3 : 2 Pull Down
The process whereby 24 FPS fi lm is converted to 29.97 FPS digital video is telecine using 3 : 2 pull
down. The 3 : 2 pull down and its related issues are a problem in the United States and Japan where
video and digital systems are derived from the National Television Standards Committee (NTSC)
standards. There is also the “advanced” pull down pattern of 2 : 3 : 3 : 2 that can be captured in real
time that is used by some digital video cameras, This is not available in telecine.
For the most part, fi lm is shot at 24 frames per second (FPS) in the United States. Film is also normally
projected at 24 FPS. This is true of both 16 mm and 35 mm. While there are digital video
formats that record and play at 24 and 23.98 FPS, often referred to as “24P” or 24-frame progressive,
standard defi nition video normally records and plays at 29.97 FPS.
One part of the 3 : 2 pull down process involves adding extra frames. In NTSC, video frames actually
consist of two interlaced “fi elds.” (For further explanation, see Appendix 1, on understanding video
formats.) The 3 : 2 process, which really should be called the 2 : 3 process as the cadence starts with
two fi elds, is shown in Figure 1.3. It takes the fi rst frame of fi lm, let’s call it the A frame, and copies
Figure 1.3 3 : 2 pull down pattern or “cadence”
3