The art of sound pictures (1930)

238 THE ART OF SOUND PICTURES By means of refinement of recording and reproduction apparatus now being exp>erimented upon, it may be possible to switch the sounds from one loud speaker to another behind the screen, in such a way that the words of one player seem to emanate from his position on the screen and the words of another player from an opposite portion of the silver sheet. These and many other refinements of sound technique are being carefully considered and experimented with, both by the big production companies and the motion picture exhibitors. Sound recording requires fifty per cent greater speed in moving the film past the camera lens than does the filming of silent pictures. This makes it necessary for both picture and sound-recording cameras to be moved at the rate of ninety feet of film per minute instead of sixty. This results in the taking of twenty-four frames per second instead of sixteen. In other words, eight more pictures, or frames, are taken each second with sound pictures than were taken in the old silent photographic process. The result of this additional number of individual pictures is greatly to slow up the movements of characters as they appear on the screen when the pictures are projected. Since a greater number of individual pictures of different stages of movement are shown, the slighter the variations of bodily position will be between each pair of pictures. Therefore, when the picture appears on the screen, the movements themselves will seem to be very much slower than in the silent pictures. This is a fact which many motion picture audiences have sensed without clearly understanding. The whole tempo of sound pictures seems noticeably slower than the tempo of silent pictures. The slowness is easily observable, though it is