SMPTE ST 241-2015 Motion-Picture Equipment - 35-mm and 70-mm Projection Reels.pdf

1、 Copyright 2015 by THE SOCIETY OF MOTION PICTURE AND TELEVISION ENGINEERS 3 Barker Avenue, White Plains, NY 10601 (914) 761-1100 Approved February 24, 2015 Table of Contents Page Foreword . 2 Intellectual Property 2 1 Scope . 3 2 Conformance Notation . 3 3 Applications 3 4 Dimensions 4 Annex A Addit

2、ional Data (Informative) . 7 Annex B Bibliography (Informative) . 8 Page 1 of 8 pages SMPTE ST 241:2015 Revision of ANSI/SMPTE 241-1995 SMPTE STANDARD Motion-Picture Equipment 35-mm and 70-mm Projection Reels SMPTE ST 241:2015 Page 2 of 8 pages Foreword SMPTE (the Society of Motion Picture and Telev

3、ision Engineers) is an internationally-recognized standards developing organization. Headquartered and incorporated in the United States of America, SMPTE has members in over 80 countries on six continents. SMPTEs Engineering Documents, including Standards, Recommended Practices, and Engineering Gui

4、delines, are prepared by SMPTEs Technology Committees. Participation in these Committees is open to all with a bona fide interest in their work. SMPTE cooperates closely with other standards-developing organizations, including ISO, IEC and ITU. SMPTE Engineering Documents are drafted in accordance w

5、ith the rules given in its Standards Operations Manual. SMPTE ST 241 was prepared by Technology Committee 20F. Intellectual Property At the time of publication no notice had been received by SMPTE claiming patent rights essential to the implementation of this Engineering Document. However, attention

6、 is drawn to the possibility that some of the elements of this document may be the subject of patent rights. SMPTE shall not be held responsible for identifying any or all such patent rights. SMPTE ST 241:2015 Page 3 of 8 pages 1 Scope 1.1 This standard specifies the dimensions of 35-mm projection r

7、eels for motion-picture and television applications and 35-mm and 70-mm projection reels intended for use on combination 70/35-mm projectors and rewinds. 1.2 This standard does not apply to shipping reels as specified in SMPTE ST 192. 2 Conformance Notation Normative text is text that describes elem

8、ents of the design that are indispensable or contains the conformance language keywords: “shall“, “should“, or “may“. Informative text is text that is potentially helpful to the user, but not indispensable, and can be removed, changed, or added editorially without affecting interoperability. Informa

9、tive text does not contain any conformance keywords. All text in this document is, by default, normative, except: the Introduction, any section explicitly labeled as “Informative“ or individual paragraphs that start with “Note:” The keywords “shall“ and “shall not“ indicate requirements strictly to

10、be followed in order to conform to the document and from which no deviation is permitted. The keywords, “should“ and “should not“ indicate that, among several possibilities, one is recommended as particularly suitable, without mentioning or excluding others; or that a certain course of action is pre

11、ferred but not necessarily required; or that (in the negative form) a certain possibility or course of action is deprecated but not prohibited. The keywords “may“ and “need not“ indicate courses of action permissible within the limits of the document. The keyword “reserved” indicates a provision tha

12、t is not defined at this time, shall not be used, and may be defined in the future. The keyword “forbidden” indicates “reserved” and in addition indicates that the provision will never be defined in the future. A conformant implementation according to this document is one that includes all mandatory

13、 provisions (“shall“) and, if implemented, all recommended provisions (“should“) as described. A conformant implementation need not implement optional provisions (“may“) and need not implement them as described. Unless otherwise specified, the order of precedence of the types of normative informatio

14、n in this document shall be as follows: Normative prose shall be the authoritative definition; Tables shall be next; followed by formal languages; then figures; and then any other language forms. 3 Applicatiions 3.1 For conventional application, the 2000-ft (610-m) capacity reel shall be preferred,

15、except in applications where the practice is to combine reels. 3.2 For television application, the 3000-ft (914-m) capacity reel shall be preferred. 3.3 The 1000-ft (305-m) capacity reel is in general use for laboratory and television applications. It should not be used in theatrical projection beca

16、use the tension on the 2-in (50.8-mm) core may be excessive. SMPTE ST 241:2015 Page 4 of 8 pages 4 Dimensions 4.1 The dimensions of the reels shall be as given in the figures and table. 4.2 Dimension F defines the area over which the reel thickness, specified by dimension C2, applies. 4.3 Dimension

17、M in Figure 2 indicates a clearance for the driving pin in the reel hub. 4.4 Figure 4 illustrates an optional spindle hole for reel capacities of 3000 ft and less, but mandatory for large-capacity, 70-mm, and 35-mm combination reels. The four driving holes are intended for use on spindles whose diam

18、eter is 0.500 in + 0.000 in - 0.005 in (12.70 mm + 0.00 mm - 0.13 mm) and driven by a pin of 0.250-in (6.35-mm) nominal diameter, engaging in one of the driving holes. 4.5 Figure 5 illustrates the standard spindle hole for use with 516-in spindles. This hole is preferred for reel capacities of 3000

19、ft and less. The vertical measurement E, Figure 5, shall be measured from the apex of the top of the round hole. 4.6 The centerlines indicated for all figures are coincident. 4.7 Dimension N in Figures 1 3 is the flange thickness, which can vary. See Annex A.5 for guidance. SMPTE ST 241:2015 Page 5

20、of 8 pages Optional system (see Section 4.4) Preferred system (see Section 4.5) SMPTE ST 241:2015 Page 6 of 8 pages Table 1 Specifications Dimensions Inches Millimeters A (1000 ft, 305 m) 9.90 + 0.00 0.02 251.5 + 0.0 5.1 A (2000 ft, 610 m) 15.00 + 0.00 0.05 381.0 + 0.0 1.3 A (3000 ft, 914 m) 16.90 +

21、 0.00 0.05 429.3 + 0.0 1.3 A (4000 ft, 1219 m) 21.75 0.03 552.4 0.8 A (4300 ft, 1300 m) 21.00 0.06 533.4 1.5 A (5600 ft, 1700 m) 23.70 0.06 602.0 1.5 A (5800 ft, 1775 m) 24.50 0.06 622.3 1.5 B (1000 ft) 1.95 0.10 49.5 2.5 B (2000 ft) 5.00 0.10 127.0 2.5 B (3000 ft) 5.00 0.10 127.0 2.5 B (4000 ft) 8.

22、00 0.03 203.2 0.8 B (4300 ft) 7.00 0.03 177.8 0.8 B (5600 ft) 8.00 0.03 203.2 0.8 B (5800 ft) 8.00 0.03 203.2 0.8 C (35-mm) 1.530 + 0.075 0.030 38.86 + 1.90 0.76 C (70-mm) 2.87 0.03 72.9 0.8 C (35-mm combination) 1.530 + 0.00 0.03 38.86 + 0.0 0.8 C1 (35-mm) 1.885 + 0.075 0.030 47.88 + 1.90 0.76 C2 (

23、35-mm up to 3000 ft) 1.625 + 0.075 0.030 41.28 + 1.90 0.76 C2 (35-mm above 4000 ft) 1.625 + 0.175 0.030 41.28 + 4.44 0.76 C2 (70mm and 35-mm combination) 3.41 0.03 86.6 0.8 D 0.317 + 0.002 0.000 8.05 + 0.05 0.00 E 0.150 0.010 3.81 0.25 F 2.25 min 57.2 min F1 2.50 min 63.5 min G 0.265 0.002 6.73 0.05

24、 H 0.782 nom 19.86 nom J 0.375 nom 9.52 nom K (diameter) 0.505 + 0.003 0.000 12.83 + 0.08 0.00 L (threading slot, 35-mm) 0.035 nom 0.89 nom L (threading slot, 70-mm and 35-mm combination) 0.060 nom 1.52 nom M 0.75 min 19.0 min SMPTE ST 241:2015 Page 7 of 8 pages Annex A Additional Data (Informative)

25、 A.1 Specifications for the reels are based on good engineering design of film-winding equipment and on minimum tension variation between hub and rim. Film tension in a projector feed and take-up mechanism should be kept low to avoid perforation damage. In order to maintain low tension where a const

26、ant-torque clutch device is used, it is necessary to keep the quotient B/A (hub diameter B divided by flange diameter A) as large as possible. In this standard, the quotient is 0.333, which maintains the initial film tension to final film tension within the 3:1 ratio. Complete interchangeability may

27、 require some adjustment in the take-up and hold-back tensions of the projector, maintaining the lowest film tension possible and still wind a full reel. A.2 In designing reels of the size and weight described in this standard, it is the practice to chamfer the spindle hole to facilitate placing the

28、 reel on the spindle. The degree of chamfer should be in accordance with good engineering practice, and should not reduce the bearing surface of the spindle hole on the spindle to the point of endangering reel stability. A.3 Although this standard does not preclude reels of other diameters or design

29、, the rim-to-hub ratio referred to in Annex A.1 remains a factor of consideration for any projector with an uncompensated constant-torque clutch in the feed or take-up mechanism. A.4 To minimize perforation damage, projector operators using large-capacity reels are cautioned against allowing film sl

30、ack to accumulate. Film wound too loosely may slip on itself causing scratches and cinch marks. A.5 For 70 mm, the newer sheet aluminum reels are not as wide as the older cast aluminum reels. Therefore spacers on the projector shafts should be used when using the newer sheet aluminum reels, one insi

31、de each reel and one outside each reel. Washers are recommended, with an inner diameter of 0.5 inches, an outer diameter of 1.25 inches, and a thickness of 0.185 inches. SMPTE ST 241:2015 Page 8 of 8 pages Annex B Bibliography (Informative) Note: All references in this document to other SMPTE docume

32、nts use the current numbering style (e.g. SMPTE ST 192:1991) although, during a transitional phase, the document as published (printed or PDF) may bear an older designation (such as ANSI/SMPTE 192-1991). Documents with the same root number (e.g. 192) and publication year (e.g. 1991) are functionally identical. SMPTE ST 192:1991, Motion-Picture Equipment (35-mm) - Shipping Reels for Prints