Journal of the Society of Motion Picture Engineers (1930-1949)

Record Details:

Title:
Journal of the Society of Motion Picture Engineers
Date:
1930-1949
Publisher:
New York, N.Y. : The Society
Volume:
Journal of the Society of Motion Picture Engineers
Leaf #:
000504
Language:
English
Collection:
Technical Journals
Format:
Periodicals
Contributor:
Prelinger Library
Sponsor:
MSN
Coordinator:
Media History Digital Library
Description:
The Journal of the Society of Motion Picture Engineers (SMPE)Êdocuments the technological progress of the film industry, highlighting technical developments in production and exhibition. Of special interest are articles about special effects, theater practices, lighting, and the introduction of the 16mm format. Initially titled "Transactions of the Journal of the Society of Motion Picture Engineers."Digitized by the Prelinger Library and the Library of Congress Motion Picture, Broadcasting and Recorded Sound Division.
Date Added:
July 19, 2022
Something wrong or inaccurate about this page? Let us Know!

Thanks for helping us continually improve the quality of the Lantern search engine for all of our users! We have millions of scanned pages, so user reports are incredibly helpful for us to identify places where we can improve and update the metadata.

Please describe the issue below, and click "Submit" to send your comments to our team! If you'd prefer, you can also send us an email to mhdl@commarts.wisc.edu with your comments.




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.

1950 MAGNETIC SOUND FILM 499 output is obtained with a bias current of approximately 80 ma (milliamperes) . Curve B refers to a soft British film; it gives its optimum output when the bias current is about 45 ma. Curve C represents the behavior of a sample of Continental stock which requires a bias current of about 70 ma in order to obtain its maximum output. 70 8O 9O IOO )n A BIAS Fig. 2. Output level of different magnetic films plotted versus bias current (A, American; B, British; and C, Continental film stock). + 15 + IO + 5 2OO 30O 5OO 2.OOO 3.OOO 5.OOO IO.OOO C.R S. Fig. 3. Frequency response of different magnetic films at optimum bias current for each film (A, American; B, British; and C, Continental film stock). Investigations also showed that different types of magnetic film stock exhibited different sensitivity and frequency responses . Figure 3 gives an example of three different types of stock in which the curves shown illustrate measurements made with the bias current adjusted to give the maximum output from each different make of film. The recording and playback equipment was adjusted in such a way as to give an almost flat response for the "British film (curve B) ; with the same adjustment a medium-hard American film (curve A) gave 10 db