We use Optical Character Recognition (OCR) during our scanning and processing workflow to make the content of each page searchable. You can view the automatically generated text below as well as copy and paste individual pieces of text to quote in your own work.
Text recognition is never 100% accurate. Many parts of the scanned page may not be reflected in the OCR text output, including: images, page layout, certain fonts or handwriting.
28
The Motion Picture Projectionist
May, 1929
New Tinted Film for Sound Pictures
(Continued from page 13) the tone quality, since sound photography heretofore has merely made the best of existing types of film.
The work leading to a negative film emulsion with the maximum effectiveness for sound reproduction was along the lines of quantitative analysis of the form of sound waves. Laboratory methods were developed by which it is possible to analyze precisely the variations in density which affect the fidelity of reproduction and to detect distortions in reproduction which are even smaller than those that could be heard by the ear.
The search for the sound negative film, like that for the tinted sound positive, was started in the Eastman Kodak Research Laboratories early in the history of soundon-film motion pictures.
In the research leading up to the development of positive film tints that would not stop the light rays to which the photoelectric cell is sensitive, work was done by the Laboratories to make a film that was tinted except for the sound track along the edge, which was clear. Such a film was successfully produced ; but, because it would make the film productions for which it was used more expensive, further efforts were made to perfect tints that could extend over the whole width of the film.
Negligible Volume Change When Tint Changes
The evenness with which the sixteen tints and the neutral tone let light through to the photo-electric cell is indicated by the fact that between a tint of maximum photo-electric density and a tint of minimum photo-electric density the change in the transmission of energy is equal to only three decibels (energy transmission units), which causes juit a barely perceptible change in the loudness of the sound. Between any tints except the two at the extremes the volume change is even less.
The problem of the research leading up to these tints was to attain such evenness of photo-electric density while at the same time covering practically the entire range of the visible spectrum with tin's as they appear on the screen.
The fact that this was accomplished means that any succession of tints may be
Give This to Your Friend — Have Him Fill It in and Mail to us at Once
The Motion Picture Projectionist
45 West 45th Street, New York City
Gentlemen :
Enclosed please find $1.50 for which you will enter my subscription to your paper for one year (12 issues) starting with issue.
I was recommended to your paper by
Name
Local No
Name
Street
City
I am a member of Local No.