1、BRITISH STANDARD BS5550-2.7.2: 1982 Cinematography Part2:16mm film Section2.7 Projection Subsection2.7.2 Specification for the performance of16mm sound-film projectors UDC 778.5.068.25:778.554.4BS5550-2.7.2:1982 This British Standard, having been prepared under the directionof the Cinematograph Stan
2、dards Committee, was published under the authority ofthe Board of BSI and comesintoeffect on 30 July1982 BSI10-1999 The following BSI references relate to the work on this standard: Committee reference CMM/27 Draft for comment79/65557 DC ISBN 0 580 12471 1 Cooperating organizations The Cinematograph
3、 Standards Committee, under whose direction this BritishStandard was prepared, consists of representatives from the following: Association of Cinematograph Television and Allied Technicians* Association of Film Laboratory Employers British Broadcasting Corporation* British Film Institute* British Ki
4、nematograph, Sound and Television Society* British Photographic Association Chartered Institution of Building Services* Cinematograph Exhibitors Association of Great Britain and Ireland* Film Production Association of Great Britain Independent Broadcasting Authority Independent Television Companies
5、Association* Royal Photographic Society* The organizations marked with an asterisk in the above list, together with the following, were directly represented on the Technical Committee entrusted with the preparation of this British Standard: Association of Independent Cinemas Association of Superviso
6、ry and Executive Engineers British Amateur Cinematographers Central Council Council for Educational Technology for the United Kingdom Electronic Engineering Association Institute of Amateur Cinematographers Lighting Industry Federation Limited National Association of Theatrical, Television and Kine
7、Employees National Audio-visual Aids Centre and Library National Illumination Committee of Great Britain Services Kinema Corporation Amendments issued since publication Amd. No. Date of issue CommentsBS5550-2.7.2:1982 BSI 10-1999 i Contents Page Cooperating organizations Inside front cover Foreword
8、iii Section 1. General 1 Scope 1 2 References 1 3 Definitions 1 4 Instruction manual and marking 1 Section 2. Design and construction 5 Design 1 6 Speed of projection 1 7 Projector lens assembly 2 8 Accessibility of optical and other parts for cleaning 2 9 Picture aperture 2 10 Framing and tilt 2 11
9、 Picture-sound separation 2 12 Electrical and safety requirements 2 13 Light source 2 14 Lamphouse ventilation 3 15 Optional facilities 3 Section 3. Picture performance 16 General 3 17 Preliminary setting up 3 18 Light output 4 19 Distribution of screen illumination 5 20 Colour bands in the image 5
10、21 Picture steadiness 6 22 Travel-ghost 6 23 Image resolution 6 24 Alignment and position of film plane 6 25 Flicker 6 Section 4. Sound performance 26 General 6 27 Projectors with photographic sound systems 6 28 Projectors with magnetic sound systems 7 29 Amplifier 7 Section 5. Mechanical tests with
11、 film 30 Test requirements 8 31 Test film 9 32 Loop tests 9 33 Fast winding without unthreading tests 9 34 Feed, reverse, still-picture, take-up and rewind tests 9 35 Loop reformer test 10 Appendix A Requirements specific to projectors with discharge lamps 12 Appendix B Alternative picture unsteadin
12、ess test film 12 Appendix C Weighting network for measurement of amplifier noise with projector not running 12 Appendix D Measurement of photographic sound system noise 12 Appendix E Test of erasure efficiency 12BS5550-2.7.2:1982 ii BSI 10-1999 Page Appendix F Test of the total system signal-to-nois
13、e ratio 13 Appendix G Warning symbol 13 Figure 1 Light output 4 Figure 2 Distribution of screen illumination 5 Figure 3 Warning symbol 13 Figure 4 Weighting curve A 14 Figure 5 Cut-outs for loop reformer test 15 Table 1 Signal-to-noise ratios for projectors with magnetic sound systems 7 Table 2 Ampl
14、ifier characteristics 8 Table 3 Take-up and rewinding 10 Table 4 Reverse take-up 10 Table 5 Perforation strain 11 Table 6 Perforation strain, reverse take-up 11 Table 7 Change of direction while running test 11 Publications referred to Inside back coverBS5550-2.7.2:1982 BSI 10-1999 iii Foreword This
15、 British Standard has been prepared under the direction of the Cinematograph Standards Committee and forms a revision of BS3675:1963 which has been withdrawn. The first edition of this standard was restricted to sound-film projectors of the fully portable type, but there is no such restriction in th
16、e present edition. Minimum performance requirements are specified for portable, transportable and installed projectors, which will assist users to evaluate all the main types of machine. A number of test films are referred to in this standard. For information on theavailability of such test films, a
17、pply to Central Enquiries Section, BritishStandards Institution,2Park Street, London W1A2BS, enclosing a stamped addressed envelope for reply. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct appli
18、cation. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pagesi toiv, pages1to16, an inside back cover and a back cover. This standard has been updated (see copyright date) and
19、 may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.iv blankBS5550-2.7.2:1982 BSI 10-1999 1 Section 1. General 1 Scope This British Standard specifies requirements for16mm sound-film projectors both for normal picture projection and in telec
20、ine channels. This standard does not apply to film mechanisms specifically designed for telecine operation. It specifies requirements intended to ensure a satisfactory picture and sound performance, safety and film life. It does not deal with the details of the mechanical and electrical design and c
21、onstruction of projectors except in so far as such details may affect performance, safety or convenience in use. 2 References The titles of the publications referred to in this standard are listed on the inside back cover. 3 Definitions For the purposes of this standard the following definitions app
22、ly. Definitions of other cinematograph terms are to be found in BS5550-8.1. 3.1 portable projector sound-film projector designed to be carried by one person and having a mass not exceeding20kg including, if provided, a detachable loudspeaker 3.2 transportable projector sound-film projector, not spec
23、ifically designed for installation but which is not a “portable projector”, which operates from a single phase power supply and which has an on-load rating not greaterthan3kVA 3.3 installed projector non-portable sound-film projector designed for permanent installation 3.4 double-headed projector so
24、und-film projector capable of transporting a separate perforated magnetic film (sepmag) in synchronism with a picture film 3.5 telecine projector sound-film projector designed or suitably modified to operate as a programme source for a video system 3.6 travel-ghost blurred effect on the screen durin
25、g film projection, with vertical tails or streaks of light, which is caused by failure of the projector shutter to cut off the light beam throughout film movement 4 Instruction manual and marking 4.1 Instruction manual. An instruction manual shall be supplied with the projector and shall give all ne
26、cessary instructions for the correct operation of the projector and for its care and maintenance(see clauses8 and12). 4.2 Marking. Projectors meeting the requirements of this standard shall be marked with the number of this standard, i.e.BS5550-2.7.2 1) . NOTESpecific labelling requirements are made
27、 in respect of the lens assembly (see clause7) and lamps (see clause13). Section 2. Design and construction 5 Design The projector shall be designed for the satisfactory projection of16mm motion-picture film complying with the requirements of the relevant Subsections of BS5550-2. The projector shall
28、 accept spools complying with BS5550-2.9 of sizes in the range120m to610m, or in the range244m to1800m in the case of an installed projector, or a greater range as specified by the projector manufacturer. The projector shall be able to transport films having splices to a maximum thickness of0.48mm w
29、ithout detriment to the projector or to the film. The projector shall satisfactorily project film which has shrunk1.0% below the minimum width specified in BS5550-2.1.1. 6 Speed of projection 6.1 The speed of projection for sound-films (except for certain applications) shall be as specified in BS555
30、0-2.7.1 when the projector is operated at its rated voltage and frequency. NOTEFor telecine and certain other synchronous applications a nominal speed of25framespersecond may be required. 1) Marking BS5550-2.7.2 on or in relation to a product is a claim by the manufacturer that the product has been
31、manufactured in accordance with the requirements of the standard. The accuracy of such a claim is therefore solely the manufacturers responsibility. Enquiries as to the availability of third party certification to support such claims should be addressed to the Director, Quality Assurance Division, B
32、ritish Standards Institution, Maylands Avenue, Hemel Hempstead, Herts HP24SQ in the case of certification marks administered by BSI or to the appropriate authority for other certification marks.BS5550-2.7.2:1982 2 BSI 10-1999 6.2 If provision is made for the projection of silent films, the speed of
33、projection for such films shall be as specified in BS5550-2.7.1. 7 Projector lens assembly The projector lens assembly shall be so designed that there shall be no change in the position of the lens sufficient to cause any impairment of focus, and/or change of image position, while the projector is r
34、unning after actuation of a locking device, if fitted. The lens assembly shall be marked with: a) relative aperture; b) focal length. 8 Accessibility of optical and other parts for cleaning All the external surfaces of the condenser lenses and of the projector lens assembly shall be accessible for c
35、leaning. If the condenser lenses have to be removed for cleaning, they shall be so designed as to facilitate their accurate replacement. The instruction manual shall give the necessary instructions for the cleaning of certain optical parts, e.g.dichroic reflectors, requiring special care. The pictur
36、e aperture, and all the surfaces which make contact with the film, shall be easily accessible for cleaning. 9 Picture aperture The effective picture aperture shall be in accordance with BS5550-2.2.2 or BS5550-6.3. If a variable aperture is provided, it shall alter the projected image area only as a
37、result of a deliberate adjustment. 10 Framing and tilt A means of framing shall be provided, giving a minimum framing movement of0.50mm both above and below the nominal position. An installed projector shall have a means of framing such that, when the framing control is operated, the position of the
38、 illuminated area on the screen is not affected. NOTEThis requirement is also highly desirable in portable and transportable projectors. Portable and transportable projectors shall have a means of elevating the projected beam through at least8 from the horizontal. An installed projector shall have a
39、 means of elevating and depressing the projected beam through at least10 and20 respectively from the horizontal. 11 Picture-sound separation The design of the projector shall be such that the film path distance from the centre of the projection aperture to the sound scanning point shall be26+0.5,1.0
40、frames for photographic sound and28+0.5,1.0 frames for magnetic sound. 12 Electrical and safety requirements The equipment shall be insulated and protected in such a manner that there shall be no danger from electrical shock or fire. The projector shall comply with the safety requirements of BS3456-
41、3.14. The projector shall comply with the requirements of BS800 regarding the suppression of radio interference. The design shall guard against the possibility of interference from external radio frequency transmissions. Lamphouses shall be designed in such a manner as to prevent the egress of mater
42、ial in the event of the lamp shattering. The instruction manual shall state that the lamp is not to be operated with the lamp shielding removed and shall include advice on the safe installation, running, removal or disposal of a lamp in respect of safety. A projector equipped with a discharge lamp s
43、hall comply with Appendix A. NOTEAccessories supplied for use with the projector should comply with the applicable safety requirements of the relevant British Standards. 13 Light source Provision shall be made to ensure that correct positioning of the lamp is maintained in use and after lamp replace
44、ment. The projector shall be marked with the type(s) of lamp(s) for which the projector is designed and the maximum wattage lamp which may be used. In the case of filament lamps the rated voltage of the lamp shall be marked on the projector. In the case of discharge lamps, the maximum rated current
45、of the lamp shall be marked on the projector. For a discharge lamp, the lamp current shall not exceed the maximum rated current of the lamp when the projector is connected to and suitably adjusted for any of its rated supply voltages.BS5550-2.7.2:1982 BSI 10-1999 3 The projector shall be so designed
46、 that the film is not damaged by overheating in normal operation, whether stationary or moving. A transportable or installed projector shall incorporate a cut-off device to interrupt the light path and protect the film against heat. The device shall be capable of being inserted manually and/or autom
47、atically between the light source and the picture aperture. Lamp caps (bases) and lamp holders shall comply with the requirements of BS5101, where applicable. NOTEManufacturers instructions or recommendations should be adhered to strictly when installing, testing, running, removing or disposing of a
48、 lamp. 14 Lamphouse ventilation 14.1 All projectors 14.1.1 General. The ventilation shall be such as to maintain the lamp temperatures within the limits specified by the lamp manufacturer during a period of3h of continuous operation, when transporting a normal projection print and using a lamp of th
49、e highest power for which the projector is designed in an ambient temperature of40 2 C 2) . 14.1.2 Test. To determine the adequacy of the ventilation, operate filament lamps at1.06times their rated voltage and operate discharge lamps at their maximum rated current or, if lower, at the maximum current specified by the projector manufacturer. If a speed control is provided, set it at minimum speed. Any heat sinks specified by the projector or lamp manufacturer are to be in position during the test. At the conclusion of the test, there sha
