How to add sound to amateur films (1954)

emphasise needle scratch from the loudspeaker and, unless you use a lightweight pick-up, record wear is increased. Long-Playing Records The long-playing type of record, running at 33£ revolutions per minute offers apparent advantages over the older standard of 78 r.p.m. The 33 J r.p.m. records play for as long as 25 minutes per side as against A\ minutes per side for the 78 r.p.m. records. Also the long-playing discs are almost unbreakable. On the other hand, they are very easily scratched by the rough treatment they are likely to receive when you make a hurried change-over in the dark. The longer playing time is of little value because it is seldom that the mood of a piece of music accurately follows that of a film for even A\ minutes. Finally, the closer pitch of the grooves makes it much more difficult to select a particular passage in a record without a mechanical aid (see p. 29). Because a work occupies so many more discs when recorded at 78 r.p.m., you stand a fair chance of finding excerpts you want on separate discs. Then, if you load these in the right order on an automatic record player, there is no need to handle records in the dark. This means you can use your radiogram directly without the need of an extension speaker. However, unless you can contrive remote control of the "Reject" knob on the auto-changer, it is better to have the radiogram near the projector. You can then reject a record partway through if the latter part of the record is unsuitable or if the music tends to lag behind the picture. Twin Turntables These difficulties vanish if you use two turntables, each provided with a separate pick-up. By lowering one pick-up as you lift the other, you can eliminate any break in the music. The transition is still rather abrupt, but can be smoothed by one of the methods described on p. 17 to 15