SMPTE ST 237-2003 Motion-Picture Film (35-mm) - Perforated DH-1870.pdf

1、 1 Scope This standard specifies the cutting and perforating dimensions for 35-mm motion-picture film with a DH-type perforation and a perforation pitch of 0.1870 in (4.750 mm). 2 Dimensions 2.1 The dimensions shall be as given in figure 1 and table 1. 2.2 The dimensions pertain to a safety film as

2、defined in SMPTE 223M. 2.3 The dimensions apply at the time of cutting and perforating for film adjusted to a temperature of 23C 1C (nominally converted to 73F 2F) and a relative humidity of (50 2)%. The manufacturer may indicate other nominal temperature and humidity conditions under which the dime

3、nsions apply. NOTES 1 The title of this standard was established by the application of a nomenclature system developed for all film dimension standards: Each title provides an indication of the film width, a code designation for the perforation shape (BH, KS, DH, or CS), or the number of rows of per

4、forations (1R, 2R, etc.), depending upon which is the significant factor, or the perforation pitch without the decimal point. 2 The metric conversion of dimension A is purposely chosen and shown to three decimal places to prevent the maximum width dimension from exceeding 35 mm. Page 1 of 3 pages SM

5、PTE 237-2003 Revision of ANSI/SMPTE 237-1998 Copyright 2003 by THE SOCIETY OF MOTION PICTURE AND TELEVISION ENGINEERS 595 W. Hartsdale Ave., White Plains, NY 10607 (914) 761-1100 Approved November 12, 2003 SMPTE STANDARD for Motion-Picture Film (35-mm) Perforated DH-1870 SMPTE 237-2003 Page 2 of 3 p

6、ages Figure 1 Dimensions Table 1 Specifications Dimensions Inches Millimeters A Film width 1.377 0.001 34.975 0.025 B Perforation pitch 0.1870 0.0004 4.750 0.010 C Perforation width 0.1100 0.0004 2.794 0.010 D Perforation height 0.0730 0.0004 1.854 0.010 E Edge to perforation 0.079 0.002 2.01 0.05 G

7、 Perforation misalignment 0.001 max 0.03 max L 100 consecutive perforation pitches 18.700 0.015 474.98 0.38 M Lateral perforation displacement 1.109 0.001 28.17 0.03 R Radius of perforation fillet 0.013 0.001 0.33 0.03 SMPTE 237-2003 Page 3 of 3 pages Annex A (informative) Additional data A.1 The us

8、er is reminded that, as a plastic, film can change dimensions temporarily due to moisture or temperature, or permanently due to solvent loss or strain effect. A.2 Film for positive use has a longitudinal pitch 0.2% longer than its companion negative. Shrinkage of the negative during aging and proces

9、sing prior to printing will generally not exceed 0.2%. Thus, the negative stock is expected to be 0.3% 0.1% shorter than the positive. This difference will minimize slippage between the two on the 12-in (305-mm) circumference sprocket of the printer, assuming a film thickness of 0.0055 in to 0.0065

10、in (0.140 mm to 0.165 mm). A.3 The uniformity of pitch, hole size, and margin (dimensions B, C, D, and E) is an important variable affecting steadiness. Variations in these dimensions, from roll to roll, are of little significance compared to variations from one perforation to the next within any sm

11、all group of consecutive perforations. As an example, the uniformity of the margin is uniquely critical for optical printing. During the printing process, the placement of the image on the film is usually with respect to successive lateral pairs of perforations at one-frame intervals. During subsequ

12、ent projection, however, the portion of the image projected is usually located, not by these perforations, but by the edge of the film. The lateral steadiness of the projected image is, therefore, directly related to the frame-to-frame uniformity of the margin. Annex B (informative) Bibliography SMPTE 223M-2001, Motion-Picture Film - Safety Film Miller, A.J. and Robertson, A.C. Motion-picture film - Its size and dimensional characteristics. Journal of the SMPTE 74(1):3-11; January 1965.