Movies for TV - Early Television Foundation

68
FUNDAMENTALS
discs which were played on an awkward turntable attached to
the film projector. As we know, this system, known as sound-ondisc,
rapidly gave way to the sound-on-film system (SOF). And
today,
all sound for movies is recorded on the film which carries
the photographic record: thus there is only one factor to consider
when handling a sound film.
Apart from the fragility of the separate record played on a
turntable, there was always the risk of losing synchronization due
to needle slip or inaccurate starting position. There is now talk
of using magnetic tape either in the form of a separate tape
running through an attachment to the projector, in synchroniza-
tion with it, or in the form of a deposit of magnetic material along
one edge of the film. The latter would be handled in much the
same manner as the photoelectric sound track. However, since
the introduction of this type of sound recording is a long way off
for it would require modification of all existing projectors to
take advantage of it it will be ignored in the discussion to fol-
low. For the purpose of this book, the only type of sound record-
ing
in which we are interested is sound-on-film.
The introduction of SOF in the late twenties necessitated a
change in the speed of projection then standard in movies this
was sixteen frames per second. The reason for the change was
merely a question of audio quality. At the old speed, film passed
through the projector at the rate of 60 feet a second: this was
insufficient to provide good audio quality due to flutter and highfrequency
cut-off. Consequently, the introduction of a new standard
of twenty-four frames a second was necessary. This meant
that at first projectors had to be capable of both speeds, since
most programs were a combination of silent and sound films. As
soon as sound films became universally popular, all projectors
were adjusted to run at twenty-four frames a second permanently.
The addition of the sound track resulted in a slight reduction in
the width of the frame, and some readers may remember seeing
one side of the black drape surrounding the screen move over to
reduce the screen width when a SOF film was about to be pro-
jected.