A Method for Determining the Scanning Loss in Sound Optical Systems

E. D. Cook, V. C. Hall

The usual methods of evaluating the frequency characteristic of sound records have been satisfactory for the determination of the required correction for overall losses. However, the losses due to aperture and optical effects are not known with sufficient precision to permit an inferior limit to be assigned to film loss only. — The method described was chosen in connection with a high-fidelity development and consists of comparing direct measurements made on images formed by contact printing a geometrically shaped test-object on the film with measurements of frequency records made using the recorder optical system. While the results obtained cannot be applied general1y as yet, due to the difficulty of correcting for variations in slit illumination. and for different gammas, the method is capable of segregating film loss from other losses for the specific conditions under which the test is conducted.

Print ISSN
Published
1938-12
Content type
Original Research
DOI
10.5594/J17345