1、SMPTE 74 93 8257401 0001240 908 SMPTE STANDARD ANSI/SMPTE 74-1 993 Revision of ANSVSMPTE 74-1988 for Motion-Picture Cameras (1 6- and 8-mm) - A Zero Point for Focusing Scales 1 Scope This standard specifies a mark and its location to indicate the film plane on 16- and 8-mm cameras having lenses whic
2、h can be focused for various object distances. 2 Specifications 2.1 The mark shall consist of a circle crossed by a line which has a length two or three times the diameter of the circle. Such a mark is shown in figure 1. 2.2 The index mark shall be placed on the out- side of the camera so that the l
3、ine across the circle coincides with the film plane in the camera aperture within 0.040 in (1 .O2 mm). 2.3 The focusing scales shall indicate object distances from the film plane. Focusing scales made in conformance with this standard may have the words “from film” appear after the word “feet” or ot
4、her unit designation. Figure 1 - Film plane mark CAUTION NOTICE: This Standard may be revised or withdrawn at any time. The procedures ofthe Standard Developer require that action be taken to reaffirm, revise, or withdraw this standard no later than five years from the date of publication. Purchaser
5、s of standards may receive current information on all standards by calling or writina the Standard Develouer. Printed in USA. Copynghto1993byTHESOCIElYOF L American National Standard MOTION PICTUREANDTELMSION ENGINEERS 595 W. Hartsdale Ave., White plains, NY 10607 (914) 761-1100 Approved June 28,1993