User Manual

Transferring Film to Tape
1504
Transferring Film to Video
Film runs at 24 fps, and NTSC video runs at 30 fps. The difference in frame rates between film
and video prevents a direct frame-to-frame transfer. To compensate, the telecine process creates
an extra six frames every second (the difference between 24 and 30). This method of creating
extra frames is known as pulldown.
At the same time, the telecine slightly reduces the film’s running speed to 23.976 fps. NTSC
video, the broadcast standard used in the United States, Japan, and other countries, plays at an
actual rate of 29.97 fps, although it is usually referred to as 30 fps. An accurate conversion
requires exact adherence to the 4:5 ratio, but this ratio breaks down when you compare 24 fps to
29.97 fps. To achieve a true 4:5 ratio, the film frame rate is slowed down to 23.976 fps. The
telecine process makes this correction automatically, slowing NTSC video 0.1 percent from the
original film speed, so that the video plays at 99.9 percent of its original speed.
The following table describes the film to video ratio:
During the capture process, your Avid editing application reverses the pulldown procedure to
capture the film footage at 24 fps. It removes the extra fields added by the pulldown process to
create full-frame, 24p media. The capture process captures video and audio at the slowed-down
speed (0.999).
Maintaining Synchronized Sound
In most cases, the sound for your production has been recorded on a digital audio system, such as
a BWF file-based recorder. You need to synchronize the sound with the picture and make sure
they are in sync in your Avid editing application. You can take one of three basic paths:
• Transfer only the picture through the telecine process to HD videotape, capture picture from
tape and sound from BWF, and sync them in your Avid editing application.
• Transfer the original sound recording to mag track, sync the mag track to the film work print,
and transfer both to videotape through a telecine process.
• Sync the original sound recordings to picture during the telecine process, and transfer both
to videotape.
If the telecine transfers sound along with picture, the sound intended to be slowed down for
telecine is usually recorded at 48.048 kHz, so that it ends up being 48 kHz.
Film Video
24 fps 30 fps
4 frames 5 frames (10 fields)
23.976 fps (0.999 x 24) 29.97 fps (0.999 x 30)