How to add sound to amateur films (1954)

sponge rubber kneeling mat is ideal. The mat may produce a little unsteadiness of the picture, but this is of no consequence during recording though it would be disastrous before an audience. The important thing is that the sponge rubber prevents the vibration of the projector from reaching the table top which can act as a sounding board. You can further improve matters by constructing a primitive tent around the projector. A convenient way is to stand two chairs on the table back to back, before and behind the projector. Then drape a blanket over the two chairs to envelop the projector but for a free space between the legs of one chair. This is for the projector beam. You can lift the blanket at one side to thread the projector and also to ventilate it at frequent intervals between recordings. 6. The ideal arrangement is to have projector and commentator separated by a sound-proof wall. There must be a window in the wall through which to project or through which the commentator may watch the picture. A serving hatch will often serve this purpose. You can mount a piece of glass in a frame made as a push fit into the hatch. The frame must be notched to accommodate the microphone lead which goes through the opening. Alternatively, you can project through a doorway. It is best then to place the microphone behind the open door, and cover most of the opening with a curtain or blanket. Film Speed When you shoot a silent film, you need think only of the picture. When you shoot a film which is to be striped, however, you must remember that sound is to be added. In 8 mm. for example, the sound quality obtained at 16 f.p.s. is barely sufficient for clear reproduction of speech. Music sounds decidedly poor. This is because the linear speed of the film is only 2-4 inches per second. Tape recorders designed to give good quality reproduction of music run at 7-5 inches per second. Running at one-third 100