five millimeter film is the professional standard format for image storage
Ample area for optical and relatively high speed of film assures good audio response. Runs at 18 inches/sec (18 frames/foot), 35 mm magnetic film can hold as many as 6 tracks of audio.
|Often the optical tracks on the projection print (2) are encoded via
the Dolby Surround process (or similar systems such as UltraStereo) which
permits 4 somewhat discrete channels: Centre, Left, Right and Surround/rear.
Film may also contain digital audio information as well.