Stereophonic Photographic Soundtracks
Ronald E. Uhlig · Journal of the SMPTE · 1973
High-quality stereophonic photographic soundtracks are now possible for 16mm and 35mm motion pictures. Each stereophonic channel is recorded in one-half the area of the normal variable-area soundtrack. The stereophonic sound is electronically processed by a commercial noise-reduction device prior to recording and printing, and restored in the projector upon reproduction. This technique provides signal-to-noise ratios in each channel which are equal to or better than those obtained on conventional photographic soundtracks. Projector modifications are simple and inexpensive. The processed stereophonic soundtrack can be compatible with unmodified monaural equipment.