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1、BRITISH STANDARD BS EN 61146-4:1998 Video cameras (PAL/SECAM/NTSC) Methods of measurement Part 4: Automatic functions of video cameras and camera-recorders The European Standard EN 61146-4:1998 has the status of a British Standard ICS 33.160.40 ? Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 1
2、3 08:09:49 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS EN 61146-4:1998 This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 December 2005 BSI 30 December 2005 ISBN 0 580 46237 4 National foreword This British Standard is the official English
3、language version of EN 61146-4:1998. It is identical with IEC 61146-4:1998. The UK participation in its preparation was entrusted to Technical Committee EPL/100, Audio, video and multimedia systems and equipment, which has the responsibility to: A list of organizations represented on this committee
4、can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search
5、” facility of the BSI Electronic Catalogue or of British Standards Online. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard does not of itself confer immunity from legal obli
6、gations. aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep UK interests informed; monitor related international and European developments and promulgate them in the UK. Summary of p
7、ages This document comprises a front cover, an inside front cover, the EN title page, pages 2 to 21 and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. DateComments Licensed Copy: sheffieldun
8、sheffieldun, na, Mon Nov 13 08:09:49 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EUROPEAN STANDARD EN 61146-4 NORME EUROPENNE EUROPISCHE NORM August 1998 ICS 33.160.40 Descriptors: Video equipment, motionpicture cameras, magnetoscope, characteristics, control functions, automatic, measurements, test
9、results, testing condition, comparison, mire, illuminance, luminance, colours English version Video cameras (PAL/SECAM/NTSC) - Methods of measurement Part 4: Automatic functions of video cameras and camera-recorders (IEC 61146-4:1998) Camras vido (PAL/SECAM/NTSC) Mthodes de mesure Partie 4: Fonction
10、s automatiques des camras video et des camscopes (CEI 61146-4:1998) Videokameras (PAL/SECAM/NTSC) Meverfahren Teil 4: Automatische Funktionen von Videokameras und Camcordern (IEC 61146-4:1998) This European Standard was approved by CENELEC on 1998-08-01. CENELEC members are bound to comply with the
11、CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or
12、to any CENELEC member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CENELEC member into its own language and notified to the Central Secretariat has the same status as the officia
13、l versions. CENELEC members are the national electrotechnical committees of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. European Committee for Electrote
14、chnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B - 1050 Brussels 1998 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members. Ref. No.
15、EN 61146-4:1998 E CENELEC Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 13 08:09:49 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Foreword The text of document 100C/221/FDIS, future edition 1 of IEC 61146-4, prepared by SC 100C, Audio, video and multimedia subsystems and equipment, of IEC TC 100,
16、 Audio, video and multimedia systems and equipment, was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as EN 61146-4 on 1998-08-01. The following dates were fixed: latest date by which the EN has to be implemented at national level by publication of an identical national stan
17、dard or by endorsement (dop) 1999-05-01 latest date by which the national standards conflicting with the EN have to be withdrawn (dow) 2001-05-01 Annexes designated “normative“ are part of the body of the standard. In this standard, annexes A and ZA are normative. Annex ZA has been added by CENELEC.
18、 _ Endorsement notice The text of the International Standard IEC 61146-4:1998 was approved by CENELEC as a European Standard without any modification. _ 2 EN 61146-4:1998 Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 13 08:09:49 GMT+00:00 2006, Uncontrolled Copy, (c) BSI 3 CONTENTS Page Clause
19、 1 Scope . 5 2 Normative references 5 3 Terms and definitions 5 4 Conditions . 6 4.1 Environmental conditions . 6 4.2 Conditions of measurement 6 4.2.1 Illumination . 6 4.2.2 Shooting conditions. 6 4.2.3 Settings of the equipment under test . 6 4.2.4 Reliability of measured results. 7 5 Method of me
20、asurement of automatic functions. 7 5.1 Automatic exposure control 7 5.1.1 Dependency on illumination level 7 5.1.2 Dependency on average brightness. 9 5.1.3 Dynamic response 12 5.2 Automatic focusing. 13 5.2.1 Assessment of focusing response time 13 5.2.2 Focusing accuracy 14 5.3 Automatic white ba
21、lance. 15 5.3.1 Dependency on colour temperature of illumination. 15 5.3.2 Dynamic characteristics of automatic white balance. 18 Annex A (normative) Specification of the tracking chart 20 Annex 2A (normative) Normative references to international publications with their corresponding European publi
22、cations . 21 Figure 1 Equipment arrangement for measurement of dependency on illumination level 8 Figure 2 Equipment arrangement for measurement of dependency on average brightness 10 Figure 3 Waveform of a horizontal line for B= 27 % 11 Figure 4 Waveform of a horizontal line for B= 77 %. 11 Figure
23、5 Waveform of a horizontal line for B= 9 %. 11 Figure 6 Typical response (1) . 12 Figure 7 Typical response (2) . 12 Figure 8 Equipment arrangement for measurement of focusing time 13 Figure 9 Equipment arrangement for measurement of automatic white balance 16 Figure 10 Colour temperature conversion
24、 block and its specification . 17 Figure A.1 Dimensional specification of the large-sized tracking chart . 20 EN 61146-4:1998 Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 13 08:09:49 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Page Table 1 Automatic exposure control Dependency on illumination
25、level 9 Table 2 Automatic exposure control Dependency on average brightness 12 Table 3 Automatic focusing Assessment of focusing response time 14 Table 4 Automatic white balance Dependency on colour temperature of illumination. 18 Table 5 Optical filters used for conversion of colour temperature. 19
26、 Table A.1 Positions of equi-centred small circles and triangle markers 20 4 EN 61146-4:1998 Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 13 08:09:49 GMT+00:00 2006, Uncontrolled Copy, (c) BSI METHODS OF MEASUREMENT Part 4: Automatic functions of video cameras and camera-recorders 1 Scope Thi
27、s part of IEC 61146 applies to the assessment of characteristics of automatic functions which are implemented in colour video cameras and camera-recorders. The performance to be assessed in this standard is limited to automatic functions relating to light input from the lens and to the electronic ou
28、tput from video cameras and the video camera portions of camera-recorders. This standard defines test patterns, measurement conditions, methods of measurement and the presentation of measured results so as to make possible the comparison of the measurement results. This standard intends to provide a
29、n objective method of measurement for each characteristic of the automatic functions but the results of objective measurements may not correlate well with the subjective assessment of automatic functions. It does not specify limiting values for the various characteristics related to automatic functi
30、ons. 2 Normative references The following normative documents contain provisions which, through reference in this text, constitute provisions of this part of IEC 61146. At the time of publication, the editions indicated were valid. All normative documents are subject to revision, and parties to agre
31、ements based on this part of IEC 61146 are encouraged to investigate the possibility of applying the most recent editions of the normative documents listed below. Members of IEC and ISO maintain registers of currently valid International Standards. IEC 61146-1:1994, Video cameras (PAL/SECAM/NTSC) Me
32、thods of measurement Part 1: Non-broadcast single-sensor cameras ISO 8341:1989, Photography Slide projectors and filmstrip projectors Illumination test 3 Terms and definitions For the purpose of this part of IEC 61146, the following definitions apply. 3.1 grey scale chart test chart which has logari
33、thmic grey steps of = 2,2 specified in item 1 of annex A of IEC 61146-1 5 EN 61146-4:1998 Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 13 08:09:49 GMT+00:00 2006, Uncontrolled Copy, (c) BSI 6 3.2 tracking chart test chart with a radial arrangement of black and white wedges (see annex A) 3.3 r
34、esolution chart test chart specified in item 4 of annex A of IEC 61146-1 3.4 uniform white chart test chart specified in item 2 of annex A of IEC 61146-1 3.5 equipment under test colour video camera and camera-recorder with electronic output(s) 4 Conditions 4.1 Environmental conditions All measureme
35、nts shall be carried out within the environmental conditions as specified by the manufacturer. The environmental conditions during measurement, at least the temperature and the relative humidity, shall be reported together with the presentation of the measurement results. 4.2 Conditions of measureme
36、nt 4.2.1 Illumination a) The illumination of test charts should be performed by two or four spot lights depending on the characteristics to be measured. b) The correlated colour temperature of the spot light shall be 3 100 K 100 K. c) Unless otherwise specified, the illumination level of the test ch
37、art shall be 2 000 lx 100 lx. d) The non-uniformity of the illumination shall be less than 5 %. e) The methods used for all the measurements shall be in line with the standard methods specified in ISO 8341. 4.2.2 Shooting conditions a) An optical axis of the equipment under test shall coincide with
38、a normal line of the test chart. b) Unless otherwise specified, the distance between the test chart and the equipment under test should be approximately 2 m. c) Unless otherwise specified, the zooming should be adjusted so that horizontal and vertical markers just fit the full frame of an under-scan
39、 monitor. 4.2.3 Settings of the equipment under test Except when otherwise indicated, the following setting shall be used: a) focus shall be adjusted for the best condition; EN 61146-4:1998 Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 13 08:09:49 GMT+00:00 2006, Uncontrolled Copy, (c) BSI b)
40、white balance shall be adjusted automatically or manually for a correlated colour temperature of 3 100 K 100 K; c) iris control of the lens may be automatic or manual; d) gain control may be automatic or manual. 4.2.4 Reliability of measured results The reliability and repeatability of measured resu
41、lts may be affected by the automation processes incorporated in the equipment under measurement. Some automatic functions may exhibit instability. Therefore, averaging of data obtained by multiple measurement may be necessary if additional precision is required. 5 Method of measurement of automatic
42、functions 5.1 Automatic exposure control 5.1.1 Dependency on illumination level 5.1.1.1 Characteristics to be measured Dependency of absolute luminance signal levels and their relative deviation on illumination level. 5.1.1.2 Measurement conditions The measurements shall be conducted using the grey
43、scale chart of = 2,2. The equipment arrangement shall be as shown in figure 1. 7 EN 61146-4:1998 Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 13 08:09:49 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN 61146-4:1998 8 Lamp Lamp Neutral density filter Equipment under test 10 000 lx Test chart Osc
44、illoscope Under-scan monitor Terminated by 75 Not terminated IEC 724/98 Figure 1 Equipment arrangement for measurement of dependency on illumination level 5.1.1.3 Method of measurement a) The test chart illuminated with 10 000 lx by lamps having a correlated colour temperature of 3 100 K 100 K shall
45、 be imaged to fill the full screen. b) The luminance signal level Y (corresponding to a white part at the centre of the test chart) relative to the blanking level shall be measured with an oscilloscope. The measurements shall be conducted with the following densities D of neutral density optical fil
46、ters placed in front of the lens: D = 0,0 (effective illumination of 10 000 lx); D = 0,7 (effective illumination of 2 000 lx); D = 1,4 (effective illumination of 400 lx); D = 2,1 (effective illumination of 80 lx). c) The measured results are noted as Y10 000, Y2 000, Y400 and Y80. Licensed Copy: she
47、ffieldun sheffieldun, na, Mon Nov 13 08:09:49 GMT+00:00 2006, Uncontrolled Copy, (c) BSI d) The dependency of luminance signal level on the illumination level shall be calculated by the following equation: R Y Y n n = 2 000 1100 % where n = 10 000, 400 and 80. 5.1.1.4 Presentation of results The abs
48、olute luminance signal levels and their relative deviations shall be reported as in table 1. Table 1 Automatic exposure control Dependency on illumination level 10 000 lx 2 000 lx 400 lx 80 lx Absolute level (mV) Y10 000 Y2 000 Y400 Y80 Relative deviation (%) R10 000 0 R400 R80 NOTE Measured results
49、 will not directly relate to a practical automatic function. The result should be understood as showing a tendency of the equipment under test. 5.1.2 Dependency on average brightness 5.1.2.1 Characteristics to be measured Luminance signal level and its relative deviation as a function of average brightness of shooting target. 5.1.2.2 Condit