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.
Modified Negative Perforation
Proposed as a Single Standard for 35-Mm Negative and Positive Motion Picture Film
By W. G. HILL
The existence of two or more perforation shapes for 35-mm films has, for many years, been considered undesirable. For processes requiring accurate film positioning, the dual Standard of Negative perforation for camera stock and Positive perforation for release stock does not suffice. Registration problems are minimized if Negative perforations are used throughout; experience, however, has shown that projection life is short. The Modified Negative perforation, with fillets at the corners, has improved resistance to tear while preserving the general negative form corresponding to conventional piloting means. Tests conducted show that better film positioning is accomplished in conventional camera and printing equipment for film with Modified Negative perforations than for film with Dubray-Howell perforations. The method of evaluating film location during exposure and printing is described and evidence of results presented. Photoelectrically recorded charts show the extent of out-of-register which resulted for various combinations of perforation types. Film-life projection tests indicate that the Modified Negative perforation is equal or superior to the Dubray-Howell perforation.
-L HE PERFORATED HOLES in motion printing and projection equipment
picture film provide a means whereby whereas pilot-pin devices are more com
the continuous strip material can be mon in cameras and step printers where
propelled in synchronism with and in the advance of the film is intermittent
register to various machine components and extreme accuracy is required. For
used in the production and reproduction many processes, such as in color film
of successive picture images. For the work, consistently accurate positioning of
most part, sprocket wheels and pilot pins the film is of utmost importance. This
are used to engage the film perforations is particularly true when more than one
and effect positioning of the film strip. negative film is used to make up the
The former are most extensively used in master, and is desirable in all reproduction processes in order to preserve screen
A paper presented on May 2, 1951, at the steadiness. The fit of the perforations
W^SlSo Divisit, JM&bZ °n <he ^^ion sprocket teeth or pi.ot
& Film Corp., Binghamton, N.Y. pins influences the degree of steadiness
108 August 1951 Journal of the SMPTE Vol.57