American cinematographer (Jan-Dec 1941)

PIONEERING IN TALKING PICTURES By LEE DE FOREST TO pioneer has always been with me an obsession. Perhaps the yearning to explore new fields was and inheritance from colonial ancestors. Vanished geographical frontiers still left far vaster regions in science and technology to explore. When early wireless began to be a bit crowded the radio telephone field, then scarcely a dream even among communication engineers, beckoned me irresistibly. This primitive beginning of the radio broadcast, in 1908, logically necessitated the development of the electronic amplifier from the audion detector tube, and thus again I managed to escape the crowd. And when, in 1912, this amplifier proved to be also an oscillator, a boundless ocean disclosing alluring archipelagoes of practical application was opened to scientific research. It then became apparent that many a forgotten dream of other early inventors might finally be brought to realization. Among such in the sea of television were the scanning disk of Nipkow, the cathode beam picture of Rossing, Cambell-Swinton's invention of the cathode-scanning beam (recently perfected in Zworykin's "Iconoscope") — all brilliant conceptions which must needs remain only blueprints and Letters Patent, for the simple lack of an inertialess amplifier of a hundred million magnifying power. Similarly in acoustics the primitive but all-embracing patent of Fritts, breaking all records, embalmed for thirty-six years in the Patent Office; and that of Elias Ries who in 1913, before the photo-electric cell, or the amplifier which could make it useful, described the remaining essentials of photographic sound-on-film recording and reproducing. So many people believe that talking pictures sprang full fledged from "The Jazz Singer" in I'.il's that we are delighted to republish this article by Dr. De Forest, which appeared in the Journal of t'ne Society of Motion Pictures Engineers. Vol. XXXVI, January, 1941. Ed. In 1919, happily unconscious of these then buried documents, I decided the time had at last arrived when sound photography should definitely give a voice to the picture film. I essayed at first three methods of sound recording, the speaking flame, the tiny incandescent filament, and the glow-tube. The latter soon showed itself to offer the only hope of practical success. My first demonstrated actual combination of sound-on-film and talking picture was at my old High Bridge, New York, laboratory in the spring of 1921, shortly before I removed to Berlin. My then assistant, William Garity, still cherishes a few film samples of himself holding the hand microphone, while I served as cameraman. This early work, when apparently only we two (and he, somewhat skeptically) believed there was a commercial future for the talking picture, evidently sank deep within his soul; for today Garity is chief factotum for Walt Disney; possibly because that primitive recording was chiefly suggestive to him of the squeaks of Mickey Mouse. It was in the spring of that year, 1921, that my difficulties in developing properly a sadly underexposed sound record and overexposed picture on the same film suggested the use of two separate, synchronized negatives, one for the picture, one for the sound, each given its proper development, and each printed successively on a common positive. My patent application covering this basic principle was finally rejected after a bitterly contested interference proceeding with that by the Tri-Ergon inventors. The destiny of this latter patent in our Supreme Court is now i icent history, familiar to all. I still maintain, however, that here resided a j ermine invention, once a total novelty, and now of tremendous practical value. Shortly after my return to America a year later, in 1922, and my installation in a genuine motion picture studio, that ancient remodelled brewery of TecArt on East 48th Street, I was visite I by Theodore Case of Auburn, X. Y. He watched my work and shortly thereafter summoned me to his laboratory to show me a gassy Western Electric amplifu r bulb whose "blue haze" was fluttering in accord with telephone currents from his microphone. Forthwith I sketched out the first oxide-coated cathode glowtube, which he and E. I. Sponable, his gifted assistant, constructed and named the "AEO light" (Dec, 1922) ; whereupon I proceeded to scrap my radiofrequency recording oscillator and metalcathode glow-tubes in favor of this lowvoltage direct-current source. I also discarded my Kuntz photoelectric cells, difficult to obtain with uniform quality, in favor of the far more sensitive Case "Thalafide" (resistance) cell, enthusiastically regardless of the fact that the latter cut off quite effectively below 3000 cycles. After this experience I returned t the use of the photoelectric cell with resultant gain in quality, and to the use of the metal cathode recording light, but designed to operate on low voltag< s, thus obviating the use of the radio-frequency oscillator of my first system. I shall refer to this feature hereafter. But now the more directly commercial requirements, following upon my] introduction of the "Phonofilm" to | Broadway audiences under the far-visioned sponsorship of Dr. Riesenfeld, at; the Rivoli and Rialto Theaters on April 15, 1923 resulted in filing early patent applications in 1923-25 on such extremely practical inventions as these: the use! of two or more picture cameras at different angles and focal distances, all synchronized to a common sound-record (Continued on Page 201) 1 CI April, 1941 American Cinemat(m;kaphkk