BS ISO 516-1999 Photography - Camera shutters - Timing《摄影技术 摄影机快门 定时》.pdf

1、BRITISH STANDARD BS ISO 516:1999 Photography Camera shutters Timing ICS 37.040.10BSISO516:1999 This British Standard, having been prepared under the directionof the Consumer Products and Services Sector Committee, was published underthe authority of the Standards Committee and comesinto effect on 15

2、October1999 BSI 03-2000 ISBN 0 580 32681 0 National foreword This British Standard reproduces verbatim ISO516:1999and implements it as the UK national standard. The UK participation in its preparation was entrusted to Technical Committee CPW/42, Photography, which has the responsibility to: aid enqu

3、irers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. A list of organizations r

4、epresented on this committee 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 Standards Catalogue under the section entitled “International Standards Corresp

5、ondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not

6、of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, theISO title page, pages ii to iv, pages1 to15 and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporat

7、ed. This will be indicated in the amendment table on the inside front cover. Amendments issued since publication Amd. No. Date CommentsBSISO516:1999 BSI 03-2000 i Contents Page National foreword Inside front cover Foreword iii Text of ISO 516 1ii blankBSISO516:1999 ii BSI 03-2000 Contents Page Forew

8、ord iii Introduction 1 1 Scope 1 2 Normative reference 1 3 Terms and definitions 1 4 Symbols 4 5 Required characteristics and their tolerances 4 5.1 Exposure time 4 5.1.1 Exposure time marking 5 5.1.2 Tolerances 5 5.2 Delay time 5 5.2.1 Front shutters 5 5.2.2 Focal-plane shutters 6 6 Test methods 7

9、6.1 General 7 6.2 Apparatus 7 6.2.1 Light source 7 6.2.2 Detector 7 6.2.3 Time-interval meter 7 6.3 Front-shutter test 7 6.3.1 Test assembly 7 6.3.2 Procedure 7 6.4 Focal-plane-shutter test 8 6.4.1 Test assembly 8 6.4.2 Procedure 9 7 Explanatory notes 9 7.1 Tolerance 9 7.2 Test method 10 Annex A (no

10、rmative) Graphic test methods 11 Figure 1 Total time for a focal-plane shutter 2 Figure 2 Front-shutter delay time 6 Figure 3 Focal-plane-shutter delay time 6 Figure 4 Test assembly for front-shutter timing measurement 7 Figure 5 Test assembly for focal-plane shutter timing measurement 8 Figure 6 Me

11、asurement of t ewith parallel ray of light and oblique ray of light 10 Figure A.1 Test assembly for front shutters 11 Figure A.2 Typical shutter traces 12 Figure A.3 Graphic method for focal plane shutter 13 Figure A.4 Focal-plane-shutter trace 13 Figure A.5 Enlarged trace 14 Table 1 Tolerances for

12、b, p, q and r 5 Table 2 Delay time of front shutter 5 Table 3 Delay time of focal-plane shutter 6 Table 4 Examples of measuring points for non-uniformity of exposure 9 Table A.1 Calculated target values of exposure times over the range of 0 C to 40 C 15 Table A.2 Calculated target values of exposure

13、 time over the range of 10 C to 0 C 15BSISO516:1999 BSI 03-2000 iii Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technica

14、l committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely wit

15、h the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part3. Draft International Standards adopted by the technical committees are circulated to the m

16、ember bodies for voting. Publication as an International Standard requires approval by at least75% of the member bodies casting a vote. International Standard ISO516was prepared by Technical Committee ISO/TC42, Photography. This third edition cancels and replaces the second edition (ISO516:1986), of

17、 which it constitutes a technical revision. Annex A forms a normative part of this International Standard.iv blankBSISO516:1999 BSI 03-2000 1 Introduction This International Standard is intended to provide a uniform basis for determining the timing and marking of exposure times of all types of shutt

18、ers used in still cameras, and to give suitable definitions of the terms used. 1 Scope This International Standard defines the characteristics of all types of shutters which are mounted in still cameras and affect the control of exposure, motion-stopping ability and synchronization with a photoflash

19、 light source. It also specifies the exposure-time markings for the shutters and their tolerances. The tolerances specified are the target values for the shutter performance that can be expected to give good results. They are not intended for application as a general inspection standard in controlli

20、ng the performance of shutters, since tolerances may vary with the feature and price class of camera tested. Test methods are described for routine manufacturing testing and quality control. 2 Normative reference The following normative document contains provisions, which, through reference in this

21、text, constitute provisions of this International Standard. For dated references, subsequent amendments to, or revisions of, such publications do not apply. However, parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent e

22、dition of the normative document indicated below. For undated references, the latest edition of the normative document referred to applies. Members of ISO and IEC maintain registers of currently valid International Standards. ISO 10330:1992, Photography Synchronizers, ignition circuits and connector

23、s for cameras and photoflash units Electrical characteristics and test methods. 3 Terms and definitions For the purposes of this International Standard the following terms and definitions apply: NOTEThe meanings of symbols used in this clause are given in clause4. 3.1 front shutter any shutter in th

24、e vicinity of the lens NOTE 1The front shutter may be in front of, behind or between the lens elements and may consist of rotating discs, rotating slats, sliding blades, oscillating blades, etc. Programmed shutters are also included. NOTE 2The common characteristic for the front shutter is that the

25、entire picture area is exposed almost simultaneously. NOTE 3When the shutter and diaphragm are located too far apart, both exposure and shutter speed may vary at different points in the picture area. 3.2 focal-plane shutter any shutter in the vicinity of the focal plane NOTE 1The focal-plane shutter

26、 may consist of fixed or variable slit curtains, rotating discs, sliding blades, etc. NOTE 2The essential feature of the focal-plane shutter is that the picture area is exposed incrementally, in such a way that the time required to expose the entire picture area is greater than the exposure time of

27、any one point. 3.3 effective time t e the best measure of the amount of light falling on the picture area as defined by the following equation (1)BSISO516:1999 2 BSI 03-2000 NOTEAt any point on the picture area, t eis generally the same for the entire picture area for front shutters when vignetting

28、is not severe. For focal-plane shutters, t ewill vary with w and V c . Equation (1) may be approximated with the equation (2) for convenience in measurement: equation (2) may only be applied under the condition of w W d s /A 3.4 exposure time t eo effective time measured at the centre of the picture

29、 area 3.5 total time t o the time for which any given point in the picture area is exposed to light see Figure 1 NOTE 1At any point on the picture area, t ois generally the same, or almost, on the entire picture area for front shutters. NOTE 2For a focal-plane shutter, however, t ois dependent on w,

30、 A, d sand V c . The curtain displacement to completely expose one point becomes w + d s /A, which can be converted to t o , if the velocity is known, using the following equation: NOTE 3This equation may be inexact in the presence of vignetting. 3.6 shutter efficiency ratio of effective time to tot

31、al time 3.7 fluctuation of exposure time p the value of p is determined by the following equation whereand are the mean and standard deviation of the values of five successive measurements (2) (3) Figure 1 Total time for a focal-plane shutter (4) (5) xBSISO516:1999 BSI 03-2000 3 3.8 ratio of two adj

32、acent exposure times q ratio of the mean values of two adjacent shutter speed settings obtained from values of five successive measurements, expressed by the following equation: NOTEt eo (n)and t eo (n + 1)are the exposure times of two adjacent shutter speed settings represented by (n) and (n +1). 3

33、.9 non-uniformity of exposure r characteristic which may be found during any single exposure due to lack of coincidence with the principal plane (front shutter) or to variations in curtain velocity or slit width (focal-plane shutters) NOTESuch non-uniformity is expressed as the ratio of the maximum

34、and minimum effective time found by exploring the picture area, and is derived from the following equation: 3.10 overall time T elapsed time for exposure of all points in the entire picture area NOTEFor front shutters, T = t o . 3.11 photoflash synchronization delay time t d time interval from the i

35、nitial closing of the shutter synchronization contacts to the moment at which the shutter element moves to the specified position (see5.2) NOTEFor details of ignition circuits of synchronizers, refer to ISO10330. 3.12 X contact synchronization contact for an electronic flash unit NOTEThe contact clo

36、ses while the shutter is fully opened to enable reception of the reflected light from the object through the aperture of the lens or for total illumination of the camera aperture. The X contact may sometimes be used for the M or MF class of photoflash lamp at the slower shutter speeds. 3.13 M contac

37、t synchronization contact for M class of photoflash lamp 3.14 FP contact synchronization contact for FP class of photoflash lamp NOTEThis contact is provided only in the focal plane shutter and may be used for M or MF class of photoflash lamp at the slower shutter speeds. (6) (7)BSISO516:1999 4 BSI

38、03-2000 4 Symbols 5 Required characteristics and their tolerances 5.1 Exposure time Theoretical exposure times that form a series are given, in seconds, by the following equation: Shutters shall be designed to provide exposure times selected from the series below, subject to the tolerances specified

39、 in5.1.2. 8,4,2,1,1/2,1/4,1/8,1/16,1/32, 1/64,1/128,1/256, 1/512, 1/1 024,1/2 048. NOTE 1Timing of the shutters should be measured at the appropriate aperture of the lens used (see Figure 4 and Figure 5). In the case of cameras that have interchangeable lenses, the standard lens should be used for e

40、xposure-time measuring. NOTE 2In evaluating shutters without lenses, exposure times should be measured under the conditions fixed so as to be equivalent to the requirements of this International Standard. NOTE 3A change in n by one unit requires a change in time by a factor of2. This unit is called

41、E vor a step. A = f-number of the lens b = exposure time error c = tolerance for exposure time d = tolerance for stop d s = distance between focal plane and curtain E o = maximum illuminance (full open shutter) E v = exposure value in units e = tolerance for exposure meter f = tolerance for film sen

42、sitivity H = exposure (time-integral of illuminance) L = film latitude m = magnification factor n = a positive or negative integer or zero p = fluctuation of exposure time, expressed in E v q = ratio of two adjacent exposure times, expressed in E v r = non-uniformity of exposure, expressed in E v s

43、= width of the mask slit in drum tester T = overall time in seconds (see Figure 3) t c = minimum contact duration in seconds t d = delay time in seconds (see Figure 2 and Figure 3) t E = theoretical exposure time In seconds see equation (8) t e = effective time in seconds (see Figure A.2) t eo = exp

44、osure time in seconds (effective time measured at the centre of the picture area) t o = total time In seconds (see Figure A.2) v c = average linear velocity of curtain v d = linear velocity of rotating drum periphery w = width of the focal-plane curtain slit = shutter efficiency (8)BSISO516:1999 BSI

45、 03-2000 5 5.1.1 Exposure time marking The exposure-time marking shall be marked as the following rounded-off values of reciprocal numbers of the series specified in5.1. Exposure times longer than1s shall not, however, be marked as reciprocal numbers, but should be made evident by color or some othe

46、r means of identification. .8,4,2, 1,2,4,8, 15,30, 60, 125, 250, 500,1 000, 2 000. The highest marking, however, need not necessarily be selected from this series, but the series beginning with the next lower number should be selected from this series, whenever practicable, and progressing as far as

47、 is required in the particular application. 5.1.2 Tolerances The tolerances of exposure time error, fluctuation of exposure times, ratio of two adjacent exposure times and non-uniformity of exposure should be as shown in Table 1 (see also7.1). The following equation, in seconds, is applicable to the

48、 tolerance of the exposure time: Table 1 Tolerances for b, p, q and r Over the range of 10 C to40 C, tie tolerances specified in Table 1 should not be exceeded, with the exception of the tolerance for b which may be exceeded by 0,25E vover the range of 10 C to0 C. Furthermore, the relative humidity

49、between 10 C and0 C should be not more than50% and between0 C and40 C not more than80%. 5.2 Delay time 5.2.1 Front shutters Delay time and minimum contact duration for synchronization shall be as given in Table 2. Table 2 Delay time of front shutter (9) Unit: E v Exposure time Quantity b a p q r 1/125 and longer 0,3 0,3 max. 1 0,45 0,2 max. shorter than 1/125 0,45 0,45 max 1 0,65 0,6 max. a The admissible values for individual exposure times are calculated and tabulated in Annex A. Type o