Sound Film Printing
The production of sound-film prints from variable density negatives by the Model D Bell & Howell printer has been studied from the point of view of high-frequency response and uniformity of product. Differences in frequency response are noted between prints made in different commercial laboratories. Individual prints in the majority of cases show variations in unmodulated track density and in the amplitude of wave envelope at high frequencies. The former are due chiefly to irregularities in the film drive and possibly to some extent to variations inherent in film. — The effect of simple mechanical filtering by the addition of a flywheel is discussed. High-frequency wave envelope irregularities result from momentary loss of contact at the printing aperture. The influence of threading, gate adjustment, printing speed, air pressure, type of illumination, degree of shrinkage, and variations in aperture height are discussed. The changes in high-frequency response produced by modifications of mechanical parts do not cover the range of difference observed among commercial prints. A part of this difference in loss characteristic is likely to be found in the developing operation.
- Print ISSN
- 0097-5834
- Published
- 1933-10
- Content type
- Original Research
- DOI
- 10.5594/J12978