BS ISO 5800-1995 Photography - Colour negative films for still photography - Determination of ISO speed《摄影技术 静物摄影用彩色负片 ISO感光度的测定》.pdf

1、BRITISH STANDARD BS ISO 5800:1987 Incorporating corrigendum June 2001 Implementation of ISO 5800:1987 Photography Colour negative films for still photography Determination of ISO speed ICS 37.040.20 BS ISO 5800:1987 This British Standard was published under the authority of the Standards Board and c

2、omes into effect on 15 March 1995 BSI 2008 ISBN 978 0 580 62730 9 National foreword This British Standard is the UK implementation of ISO 5800:1987, incorporating corrigendum June 2001. It supersedes BS 1380-3:1980 which is withdrawn. This British Standard is published under the direction of the Con

3、sumer Products and Services Sector Board and its preparation was entrusted to Technical Committee CPM/10. NOTE International and European Standards, as well as overseas standards, are available from Customer Services, BSI, 389 Chiswick High Road, London W4 4AL. This publication does not purport to i

4、nclude all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard cannot confer immunity from legal obligations. Amendments/corrigenda issued since publication Date Comments 30 June 2008 Implementation of ISO corrigendum June 200

5、1, text modified in 5.5BS ISO5800:1987 ii BSI 2008 Contents Page Foreword iii 0 Introduction 1 1 Scope and field of application 1 2 References 1 3 Definitions 1 4 Sampling and storage 1 5 Method of test 2 5.1 Principle 2 5.2 Safelights 2 5.3 Exposure 2 5.3.1 Sample condition 2 5.3.2 Type of sensitom

6、eter 2 5.3.3 Radiant energy quality 2 5.3.4 Modulation 2 5.3.5 Exposure time 2 5.4 Processing 2 5.4.1 Conditioning of samples 2 5.4.2 Processing specifications 2 5.5 Densitometry 2 5.6 Evaluation 3 5.6.1 Sensitometric curve 3 5.6.2 Minimum densities 4 5.6.3 Determination of H m 4 6 Product classific

7、ation 4 6.1 ISO speed scale 4 6.2 ISO speed of a product 4 6.3 Accuracy 4 7 Product marking and labelling 4 Figure Method for determining speed 3 Table ISO speed scales 4BS ISO5800:1987 BSI 2008 iii Foreword ISO (the International Organization for Standardization) is a worldwide federation of nation

8、al standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical 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. Internatio

9、nal organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. Draft International Standards adopted by the technical committees are circulated to the member bodies for approval before their acceptance as International Standards by the ISO Council. They are ap

10、proved in accordance with ISO procedures requiring at least75% approval by the member bodies voting. International Standard ISO5800 was prepared by Technical Committee ISO/TC42, Photography. This second edition cancels and replaces the first edition (ISO5800:1979), of which it constitutes a technica

11、l revision. Users should note that all International Standards undergo revision from time to time and that any reference made herein to any other International Standard implies its latest edition, unless otherwise stated.iv blankBS ISO5800:1987 BSI 2008 1 0 Introduction Satisfactory prints can gener

12、ally be obtained from colour negative films over a significant range of exposure provided that suitable adjustments are made in the printing operation. The underexposure latitude is approximately one camera exposure value unit (camera stop or E v ) when film speed is determined using this Internatio

13、nal Standard. Overexposure latitude of a colour negative film can be as large as3E v . In other words, if a colour negative film has a speed of ISO100, it may give satisfactory results if it is exposed anywhere from ISO12 to ISO200. Photographers, on the average, tend to underexpose film, particular

14、ly in simple cameras, 1)as a result of their desire to record events under cloudy conditions or in the shade. Some cameracartridge systems are designed to take advantage of the overexposure latitude of colour negative films to improve results when pictures are taken under these circumstances. This i

15、s accomplished by overexposing the film under sunlight conditions to increase the underexposure latitude of the system. For example, a126-size cartridge containing film with an ISO speed of100 may be coded for ISO64 speed. This International Standard is a revision of ISO5800:1979 to update the forma

16、t of presentation and to reference new ISO standards which more precisely describe illuminants and densitometry specified for use. No differences in speed values should result from the changes made to the International Standard. 1 Scope and field of application This International Standard specifies

17、the method for determining the ISO speed of colour negative camera films for pictorial still photography. It is assumed that the colour negatives obtained with these films will be used to make reflection-type colour prints primarily but may also be used to make colour transparencies. The speeds obta

18、ined by application of this International Standard are intended for practical use with exposure meters, exposure calculators, and exposure tables. This International Standard does not apply to colour negative films for motion-picture and aerial photography or for making intermediate negatives. 2 Ref

19、erences ISO5, PhotographyDensity measurements Part1: Terms, symbols and notations Part2:Geometric conditions for transmission densityPart3: Spectral conditions. ISO554, Standard atmospheres for conditioning and/or testingSpecifications. ISO2720, PhotographyGeneral purpose photographic exposure meter

20、s (photoelectric type) Guide to product specification. ISO2721, PhotographyCamerasAutomatic controls of exposure. ISO7589, PhotographyIlluminants for sensitometrySpecifications for daylight and incandescent tungsten. 3 Definitions For the purpose of this International Standard, the following definit

21、ions apply. 3.1 speed a quantitative measure of the response of the photographic material to luminous energy for the specified conditions of exposure, processing, density measurement, and analysis 3.2 exposure (H) the time integral of illuminance on the film, measured in lux seconds, and designated

22、by the symbol H exposure is often expressed in log 10H units 3.3 exposure value unit a unit used for an exposure change by a factor of2 or change of0,30 log 10H units. To be in compliance with ISO2720, this will be denoted as1E v changing exposure may be accomplished by changing exposure time, illum

23、ination level, or filters over the lens 4 Sampling and storage In determining the ISO speed of a product, it is important that the samples evaluated yield the average results obtained by users. This will require evaluating several different batches periodically under the conditions specified in this

24、 International Standard. Prior to evaluation, the samples shall be stored according to the manufacturers recommendations for a length of time to simulate the average age at which the product is normally used. Several independent evaluations shall be made to ensure correct calibration of equipment an

25、d processes involved in determining film speed. Thebasic objective in selecting and storing samples as described above is to ensure that film characteristics are representative of those obtained by a photographer at the time of use. 1) Such as those with one shutter speed and two aperture stops.BS I

26、SO5800:1987 2 BSI 2008 5 Method of test 5.1 Principle Samples are exposed and processed as specified below. Density measurements are obtained from the resultant images to produce a sensitometric curve from which values are taken and used to determine ISO speed. 5.2 Safelights To eliminate the possib

27、ility of safelight illumination affecting the sensitometric results, all films shall be handled in complete darkness to avoid exposing the emulsion to unintentional radiation during sample preparation, exposing and processing. 5.3 Exposure 5.3.1 Sample condition During exposure, the samples shall be

28、 at a temperature of23 2 C and in equilibrium with a relative humidity of (50 5)%. 5.3.2 Type of sensitometer The sensitometer shall be a non-intermittent, illuminance-scale type. 5.3.3 Radiant energy quality The appropriate illuminant for the particular film type being exposed shall conform to the

29、specification given in ISO7589. ISO speed may be determined using ISO sensitometric daylight, studio tungsten, or photoflood illuminants. Since the speed of film/process combinations will depend on the type of illuminant used for determining ISO speed, the illuminant should be specified in the instr

30、uctions. 5.3.3.1 Filters ISO speed shall be specified for use without a filter in front of the camera lens. If film is used with a colour filter in front of the camera lens, an “equivalent” speed number can be used to determine the exposure of the film with the filter. ISO speed does not apply to th

31、e filtered condition. 5.3.4 Modulation The total range of spectral diffuse transmission density with respect to the film plane of each area of the light modulator throughout the wavelength interval from400 to700nm shall not exceed5% of the average density obtained over the same interval or0,03densit

32、y, whichever is greater. In the interval from360 to400nm,10% of this same average density, or0,06 density, whichever is greater, is acceptable. If stepped increments are used, the logarithm to the base10of the exposure increment shall not be greater than0,20. The width and length of a single step sh

33、all be adequate to obtain a uniform density within the reading aperture specified for densitometry. If a continuous variable modulator is used, the logarithm to the base10of the change in exposure with distance along the test strip shall be uniform and not greater than0,04permillimetre. 5.3.5 Exposu

34、re time The exposure time shall correspond with the usage practice for the particular film tested. Since the speed of film may be dependent on the exposure time because of reciprocity law failure, the exposure time used for determining the ISO speed should be specified when quoting values. 5.4 Proce

35、ssing 5.4.1 Conditioning of samples In the time interval between exposure and processing, the samples shall be kept at23 2 C and a relative humidity of (50 5)%. The processing shall be completed in not less than5days and not more than10days after exposure for general-purpose films, and not less than

36、4h and not more than7days for professional films. 5.4.2 Processing specifications No processing specifications are described in this International Standard in recognition of the wide range of chemicals and equipment used. ISO speeds provided by film manufacturers generally apply to the films when th

37、ey are processed in accordance with their recommendations to produce the photographic characteristics specified for the process. Process information shall be available from film manufacturers or others who quote ISO speed. This shall specify the chemicals, time, temperature, agitation equipment, and

38、 procedure used for each of the processing steps and any additional information required to obtain the sensitometric results described. The values for speed obtained using various processing procedures may differ significantly. Although different speeds for a particular film may be achieved by varyi

39、ng the process, other sensitometric and physical changes may also accompany the speed changes. 5.5 Densitometry ISO standard Status M diffuse transmission densities of the processed images shall be measured using a densitometer complying with the geometric conditions specified in ISO5-2 and the spec

40、tral conditions specified in ISO5-3.BS ISO5800:1987 BSI 2008 3 5.6 Evaluation 5.6.1 Sensitometric curve The ISO standard red, green, and blue Status M diffuse transmission density values are plotted against the logarithm to the base10 of the corresponding exposure (H) expressed in lux seconds, to ob

41、tain three sensitometric curves similar to those illustrated in the Figure. Figure Method for determining speed Readings shall be made in a uniform area of the image, typically at least 1 mm from the edges of the exposures.BS ISO5800:1987 4 BSI 2008 5.6.2 Minimum densities The red, green, and blue m

42、inimum densities shall be determined from an unexposed sample of the same film processed simultaneously with the film exposed for determining the sensitometric curve. 5.6.3 Determination of H m Speed is calculated from the exposures required to produce red, green, and blue densities that are0,15abov

43、e the corresponding minimum density values for each of the three curves. The exposure, H m , is computed by the use of the formula: The exposure, H m , represents the sensitometric parameter from which speed is computed. If the green layer is also the slowest, H mwill equalH Green . 6 Product classi

44、fication 6.1 ISO speed scale The speed scales given in the table are derived from the formulae: Arithmetic speed: Logarithmic speed: “ISO” speed shall be obtained directly from log 10H mby use of the table which shows the rounding method to be used. 6.2 ISO speed of a product The ISO speed of a prod

45、uct (as distinguished from that of a specific sample) shall be based on the arithmetic average of the logarithms of exposures, log 10H m , determined from various batches of the product when selected, stored, and tested as specified as above. The ISO speed of a product with proper rounding is then d

46、etermined from the average value of log 10H m , by use of the table. Since ISO speed is dependent on exposure and processing conditions, these should be indicated when quoting ISO speed values. Table ISO speed scales 6.3 Accuracy The calibration of the equipment and processes involved in determining

47、 film speed shall be adequate to ensure that the error in log 10H mis less than0,05. 7 Product marking and labelling Speed of a product determined by the method described in this International Standard and expressed on the scales of the table may be designated ISO speed and denoted in the form of IS

48、O100, ISO21, or ISO100/21. However, since the speed is dependent on the illuminant, exposure time, and process used, these conditions should be clearly indicated, whenever possible, when quoting values. log 10H m ISO speed from to arithmetic logarithmic 3,40 3,30 3,20 3,10 3,00 2,90 2,80 2,70 2,60 2

49、,50 2,40 2,30 2,20 2,10 2,00 1,90 1,80 1,70 1,60 1,50 1,40 1,30 1,20 1,10 1,00 0,90 0,80 0,70 0,60 0,50 3,31 3,21 3,11 3,01 2,91 2,81 2,71 2,61 2,51 2,41 2,31 2,21 2,11 2,01 1,91 1,81 1,71 1,61 1,51 1,41 1,31 1,21 1,11 1,01 0,91 0,81 0,71 0,61 0,51 0,41 3200 2500 2000 1600 1250 1000 800 640 500 400 320 250 200 160 125 100 80 64 50 40 32 25 20 16 12 10 8 6 5 4 36 35 34 33 32 3