Projection engineering (Sept 1929-Nov 1930)

Projection Engineering, May, 1930 Page 11 Fig. 12. Hookup for prog r a m transmission. short, one reel stories in silhouette, showing prize fights and similar action. This paper has not dealt with the problems of reception, but may I say here that these silhouettes are utilized, not because of the incapabilities of the transmission equipment, but because of the fact that few shortwave receivers now in use meet the standards of performance necessary for delineation of half-tone subjects. That is, a fidelity characteristic flat to within a few per cent, from 15 Fig. 13. Coupling to antenna system. cycles up to 30 kilocycles, with little harmonic distortion at high percentages of modulation. We also transmit, though not yet on our regular schedule, direct pickup subjects, and are planning to add this feature to our daily program within the next few weeks — -with sound. Number of Picture Elements There has been much said in the press with regard to the number of picture elements necessary to create an image of marked perfection. Some of this publicity has been quite misleading. We know from experience that a picture of 576 elements is of interesting detail, that a 900 element il3ttl,;Sl|iH:;iitt!t;& image presents a vast improvement over that, and that a picture of 2300 elements (such as we employ), still offers a marked improvement, but the transition from 2300 to 3600 does not give the approach toward perfection that would be supposed. We might, therefore, formulate a law for the variation of apparent perfection obtained by increased number of pic dP ture elements where — — = the slope dN of the curve in Fig. 14 is equal to KP where K must remain a constant as yet undetermined and P and N are respectively the degree of perfection and the dp number of elements. = KP dN Fig. 14. Picture elements. We assume, as you see, that the curve takes on a logarithmic aspect and that the improvement observed, with a vast change in the number of picture elements, becomes slight as we approach the complete perfection only obtainable with an infinite number of elements. The human senses are readily imposed upon and the power of sight is most fallible. With a knowledge of what has already been done, even with the crude methods now employed it is easy to imagine that an image, but slightly removed from true perfection, can be transmitted without exceeding our present band of 100 kc, provided that that band be subjected to all the rigorous economies of present day communication engineering. The television image must not be compared with a newspaper half-tone of equivalent definition, as the apparent excellence is enhanced by the added effect of motion and by the addition of sound. We are prepared to televise with sound, such items as, prize fights, athletic events covering small area, addresses of important personages, etc. We have recently conducted reliability tests in connection with a public demonstration of synchronized sight and sound in Newark, N. J., and also at the recent Jersey City Radio Show. Those of you who were fortunate enough to witness these demonstrations will no doubt concur with me regarding their success. A SOUND PICTURE SLANG Enviably detached, movie men called their western pictures "horse opera." With gentlemanly ideals always uppermost, they dubbed the actor seeking undue prominence a "lens-louse." And now about the sound-picture also, there gathers the special language of the adept for his trade and the devotee for his art. The sound expert, when he travels in highbrow circles, styles himself an "acoustician." On the set, however, he is known, without loss of self-respect, by somewhat less complimentary terms. The sound-picture fraternity have developed a special vocabulary, brief as a ballet-skirt and no less expressive, for the complex ideas of their technique. Here are a few phrases, culled from various sources. Apple — amplifier tube BUmp — sound-proof hood over camera. Also known as bungalow and baby booth. Cans — headset sometimes used by the mixer operator Dubbing — re-recording of sound by electrical methods Freeh — frequency (of alternation) Flats — surfaces for construction of sets Gobo — light shield to protect camera lens Hards — arc lights for illuminating sets Inkies — incandescent lamps In Sink — in synchronism Mike — the Great Joss of the talkiesotherwise, the microphone Pan Stock — panchromatic film Pec — photoelectric cell Props — stage properties and the men who handle them Rushes — prints of the previous day's shooting, processed in a hurry for review. Also called dailies Soup — film developing solution Stew — undesired sounds String — light valve ribbon When something often done before must be done again right away, a wealthy noun and a gutty verb supplant the lengthy latinisms of leisure. Thus, at the shout "Lock 'em up!" camera men are consigned to their soundproof booths. Orders for the steps in synchronizing cameras and recorders are: "Interlock" or "sink 'em." In a moment the word comes back "Sunk!" Final pleas to the actors for "quiet" — then "Turn 'em over." The return "Red light" means that cameras and recorders are up to speed. Action begins, to end with the director's shout "cut" at the close of the scene. Bell Laboratories Record