History of Sound Motion Pictures by Edward W Kellogg Third Installment
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History of Sound Motion Pictures by Edward W Kellogg Third Installment History of Sound Motion Pictures by Edward W Kellogg Our thanks to Tom Fine for finding and scanning the Kellogg paper, which we present here as a “searchable image”. John G. (Jay) McKnight, Chair AES Historical Committee 2003 Dec 04 Copyright © 1955 SMPTE. Reprinted from the Journal of the SMPTE, 1955 June, pp 291...302; July, pp 356...374; and August, pp 422...437. This material is posted here with permission of the SMPTE. Internal or personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution must be obtained from the SMPTE. By choosing to view this document, you agree to all provisions of the copyright laws protecting it. FINAL I NSTA-LLMENT History of Sound Motion Pictures By EDWARD w. KELLOGG For the abstract of this paper which was presented on May 5,1954, at the Society's ing is reported by J. Crabtree in the Convention at Washington, D.C., see the first installment published in the June October 1933 and February 1934 Jour- Journal. The second installment appeared in the July Journal. See p. 437 for nals.232 errata in second installment. In 1934 C. N. Batsel described a non- slip contact printer2= employing a prin- ciple proposed and demonstrated earlier Developments Which Extended differs from this assumed average. By me- by A. V. Bedford for a different applica- the Frequency Range chanically stretching whichever film is tion.7@,234Bending a film stretches one shorter, two films can be moved together face and compresses the other, and it is Better Light-Modulating System for Vari- through an appreciable distance in per- only necessary that the contacting sur- able Area. Mention was made in the fect nonslipping contact. A printing sys- faces of the two films be made equal. section on loudspeakers of a demonstra- tem in which this was done was developed In the nonslip printer, the negative is tion by Dimmick and BelaP9 of sound by the Technicolor engineers for their rolled through the machine at fixed with extended frequency range. Aside color transfer, but it was not used for curvature, and the print stock (held from the 'improved loudspeakers and the sound prints. An extended investigation against the negative at the printing ribbon microphone (whose response was of the losses and irregularities in high-fre- point, where it is propelled solely by practically uniform from 60 to 10,000 quency response which result from slip- friction) is made automatically to assume cycles) there were a number of advances page and imperfect contact during print- the curvature at which identical numbers that contributed to the result. The new galvanometer and optical system made so much more light available that it was feasible to reduce the width of the April 8, 19.30. A V BEOFORD 1,754,187 recording beam to 4 mil, thus improving 8ELT OR STRIP DRIVING ARRANGEMENT resolution. No small factor in giving clean high frequencies is avoidance of flutter, Filed Nov 5. 1927 particularly rapid flutter such as 96 cycles. In the demonstrations, both Fig. I recording and reproduction were on magnetic-drive machines. * (The rotary R stabilizer was not yet available.) E f-' Ground-nois: reduction was by gal- vanometer bias with a single narrow line of transparent film when the modula- tion was zero, and it is my recollection that a measurement indicated a ratio better than 50 db between signal at full modulation and the ground noise when biased for zero modulation. Nonslip Printer and Improved Sprocket- Type Printers. With the sprocket-type contact printers in almost universal use, a certain amount of slipping of the nega- tive with respect to the print film is almost inevitable. The curvature at the sprocket compensates for a certain negative shrink- Fis.2. age at which the ratio of radii of the shrunk negative and unshrunk print stock is just equal to the ratio of their lengths. The sprocket diameter is designed to make this compensation correct for an average negative shrinkage, but it will be only ap- proximate for negatives whose shrinkage *The special film-phonograph used in the demonstrations was a prototype of those used in the Disney Fantasia reproduction (see Fig. 7, p. 136, Jour. SMPE, Aug. 1941). The film was pulled by the magnetically driven drum over a curved supporting plate where the tracks were scanned, and was steadied at the other end of the plate by another drum with flywheel. This was an anticipation of the double flywheel system Fig. 17. Control of film speed .by flexure (A. V. Bedford). Principle later used in now used with magnetic tape and film. nonslip printer. 422 August 1955 Journal of the SMPTE Volume 64 of sprocket holes are fed through in a comes up only with 35mm-to-35mm nition was the fact that ultraviolet light given time. printing, for which optical printers are is more rapidly absorbed in the emulsion The nonslip printer was not built for rarely used. than is visible light. The increased sale by RCA, but free license and draw- In spi%e of such improvements as absorption must be compensated for by ings were offered, and numerous labora- have been made in developer turbulation increased intensity, but the net effect is tories built and used them, notably in the processing machines, the sprocket that the exposure is confined more nearly Consolidated Film Industries in Holly- type of printer does not appear to have to the surface where the silver halide wood and Ace Film Laboratory in any strong competitor for density prints. grains are more completely used, and the Brooklyn.23 In such a situation the efforts of several result is less graininess. Most important A printer based on the identical prin- Eastman engineers”2.113 to improve of all is that the light scattered by the ciple was developed independently by sprocket action are well justified. The emulsion does not spread as far sidewise, R. V. Wood.”6 shrinkage-compensating sprocket de- and thus enlarge the image, as does Although nonslip printers were not scribed above under “Mechanical Sys- visible light.N2s2a made in large numbers, and did not to tems” should result in great improve- Dimmick reported the results of tests any great extent displace the con- ments. The new film-base materials with with ultraviolet in August 1936.2u He ventional sprocket type of contact printer, their reduced shrinkage should also make had found it possible to obtain adequate they served to demonstrate how much for better results with printers of the exposure with the regular incandescent improvement was possible through better sprocket type.391 lamps and Corning No. 584 filters. printing, and in this way stimulated Conversion for ultraviolet recording makers and users of sprocket printers to Optical Printers. Cost and quick produc- involved provision for the filter, redesign improve their machines and maintain tion have been dominating considera- of the objective lens, and substitution of them in the best possible condition. tions in much 16mm production, and glasses with less ultraviolet absorption In a number of laboratories it appeared contact printing on the sprocket has pre- for other lenses in the system. Many of that better prints resulted if the teeth vailed, the printers being simpler than the variable-area recording systems were were removed from the side of the other types and available in large num- converted. Single-film newsreel systems sprocket next to the soundtrack, leaving bers to meet the heavy wartime de- (with the sound recorded on panchro- only a smooth supporting rim. The mands. However, registration of nega- matic negatives) were especially benefited theory behind this is not clear unless it tive and positive perforations is not a by use of ~ltraviolet.~~~,~~~ is that such disturbances of contact as factor in the quality of 16mm prints of The results obtainable by the applica- are due to film sticking on the teeth are either density or area tracks. There is tion of ultraviolet exposure to variable- thus kept further from the soundtrack. thus no obstacle on this score either to density films were studied and reported There were two reasons which limited nonslip printers or to optical printers by Frayne and Pagliarulo in June 1949.247 the use of the nonslip printer. Since with independently filtered film motion, They found major improvement in there is a very narrow region of close and both types have been used, the definition and reduced distortion, but contact: the printing beam had to be nonslip for printing from 16mm nega- only about 1 db reduction in ground narrow. Under such conditions any tives, and the optical principally for noise. Further experiences with ultra- speed irregularities cause variation in printing on 16mm film from 35mm nega- violet are reported by Daily and print exposure, which sometimes be- tive~,=~-~~~but also with a 1 : 1 optical Chambers.248 comes audible in density prints. While system for printing from 16mm negatives Many printers were modified to print there is no valid excuse for such speed (Precision Film Laboratories, New sound with ultraviolet. High-intensity variations, this trouble contributed to the York) mercury arc lamps were widely used for conclusion that the nonslip printer was The Eastman Co. has designed several the printers. unsatisfactory for density printing. Film models of optical reduction printers Ultraviolet exposure gives lower laboratory operators were naturally in which the 35mm and 16mm films gamma for the same development than averse to maintaining one type of printer are on sprockets on opposite ends of a does white light.