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1、BRITISH STANDARD BS ISO 2240:1994 Implementation of ISO 2240:1994 Photography Colour reversal camera films Determination of ISO speed Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 12:39:14 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS ISO 2240:1994 This British Standard, having been prepare
2、d under the direction of the Consumer Products and Services Sector Board, was published under the authority of the Standards Board and comes into effect on 15 March 1995 BSI 01-2000 The following BSI references relate to the work on this standard: Committee reference CPM/10 Draft for comment 93/3055
3、19 DC ISBN 0 580 23905 5 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Consumer Products and Services Sector Board to Technical Committee CPM/10, upon which the following bodies were represented: British Association of Oral and Maxillo
4、-Facial Surgeons British Dental Association British Mimetograph, Sound and Television Society British Photographic Association College of Radiographers Institute of Physics Ministry of Defence Photogrammetric Society Pira International Amendments issued since publication Amd. No.DateComments License
5、d Copy: sheffieldun sheffieldun, na, Sun Nov 26 12:39:14 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS ISO 2240:1994 BSI 01-2000i Contents Page Committees responsibleInside front cover National forewordii Forewordiii Text of ISO 22401 Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 12:39:14 G
6、MT+00:00 2006, Uncontrolled Copy, (c) BSI BS ISO 2240:1994 ii BSI 01-2000 National foreword This British Standard reproduces verbatim ISO 2240:1994 and implements it as the UK national standard. It supersedes BS 1380-2:1984 which is withdrawn. This British Standard is published under the direction o
7、f the Consumer Products and Services Sector Board whose Technical Committee CPM/10 has the responsibility to: aid enquirers to understand the text; present to the responsible international committee any enquiries on interpretation, or proposals for change, and keep UK interests informed; monitor rel
8、ated international and European developments and promulgate them in the UK. NOTEInternational and European Standards, as well as overseas standards, are available from Customer Services, BSI, 389 Chiswick High Road, London W4 4AL. A British Standard does not purport to include all the necessary prov
9、isions of a contract. Users of British Standards are responsible for their correct application. 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, pages i and ii, the ISO title p
10、age, pages ii to iv, pages 1 to 6 and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 12:39:14 GMT+00:00 2006, U
11、ncontrolled Copy, (c) BSI Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 12:39:14 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ISO 2240:1994(E) ii BSI 01-2000 Contents Page Forewordiii Introduction1 1Scope1 2Normative references1 3Definitions1 4Sampling and storage2 5Test method2 6Product clas
12、sification4 7Product marking and labelling4 Annex A (informative) Bibliography6 Figure 1 Sensitometric curve3 Table 1 ISO speed5 Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 12:39:14 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ISO 2240:1994(E) BSI 01-2000iii Foreword ISO (the International
13、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 technical committees. Each member body interested in a subject for which a technical committee has been esta
14、blished 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 with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardiza
15、tion. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. International Standard ISO 2240 was prepared by Technical Committee
16、 ISO/TC 42, Photography. This second edition cancels and replaces the first edition (ISO 2240:1982), of which it constitutes a technical revision. Annex A of this International Standard is for information only. Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 12:39:14 GMT+00:00 2006, Uncontrol
17、led Copy, (c) BSI iv blank Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 12:39:14 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ISO 2240:1994(E) BSI 01-20001 Introduction ISO speeds are intended to provide correct exposures with exposure meters conforming to ISO 2720, and, where applicable, au
18、tomatic exposure controls for cameras conforming to ISO 2721; the resultant camera exposure will normally lead to colour transparencies or motion pictures of the best quality. For an average scene and average camera, the indicated camera exposure will be approximately midway between the least exposu
19、re and the greatest exposure required to produce transparencies and motion-picture films suitable for viewing at normal luminance levels. For the purposes of this International Standard, the normal luminance of transparency illuminators is assumed to be that described in ISO 3664, with a ratio of di
20、rect-to-ambient luminance of about 40 : 1. The normal luminance of transparency projection screens is assumed to be about 137 cd/m2. Screen luminance of 8 mm Type R and 8 mm Type S (Super-8) motion-picture film projection is assumed to range from approximately 40 cd/m2 (see ISO 2910) to 62 cd/m2. Th
21、erefore, it may be desirable to increase exposure by 25 % above that obtained by using the speed derived by following the sensitometric procedure described in this International Standard. Many camera manufacturers design and calibrate their 8 mm Type R and 8 mm Type S motion-picture cameras with an
22、adjustment which permits more exposure to compensate for the lower screen luminance of the usual projection conditions (see ISO 2721). 1 Scope This International Standard specifies the method for determining the ISO speed of colour reversal camera films producing continuous-tone pictorial images tha
23、t are intended to be viewed on transparency illuminators or by projection as slides. It also applies to 8 mm and 16 mm motion-picture films used in non-professional applications. This International Standard does not apply to professional motion-picture films regardless of their applications. 2 Norma
24、tive references The following standards contain provisions which, through reference in this text, constitute provisions of this International Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this Intern
25、ational Standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. ISO 5-2:1991, Photography Density measurements Part 2: Geometric conditions for
26、transmission density. ISO 5-3:, Photography Density measurements Part 3: Spectral conditions1). ISO 7589:1984, Photography Illuminants for sensitometry Specifications for daylight and incandescent tungsten. 3 Definitions For the purposes of this International Standard, the following definitions appl
27、y. 3.1 exposure, H2) time integral of illuminance on the film, measured in lux seconds NOTE 1Exposure is often expressed in log10H units. 3.2 speed quantitative measure of the response of the photographic material to radiant energy for the specified conditions of exposure, processing, density measur
28、ement and analysis 3.3 minimum density minimum density value obtainable following the process used in the ISO speed determination 1) To be published. (Revision of ISO 5-3:1984) 2) International Lighting Vocabulary, CIE Publ. No. 17.4, 1987, luminous exposure, H. In this International Standard, “lumi
29、nous exposure” is simply referred to as “exposure”. Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 12:39:14 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ISO 2240:1994(E) 2 BSI 01-2000 4 Sampling and storage In determining the ISO speed of a product, it is important that the samples evaluated y
30、ield the average results obtained by users. This will require evaluating several different batches periodically under the conditions specified in this International Standard. Prior to evaluation, the samples shall be stored according to the manufacturers recommendations for a length of time to simul
31、ate the average age at which the product is normally used. To assure that all components of variance are included in the sampling plan, it is recommended that procedures such as those outlined in ISO Standards Handbook 3 be used. The objective in selecting and storing samples as described above is t
32、o ensure the film characteristics are representative of those obtained by a photographer at the time of use. 5 Test method 5.1 Principle Samples are exposed and processed in the manner specified below. Density measurements are obtained from the resultant images to produce a sensitometric curve from
33、which values are taken and used to determine ISO speed. 5.2 Safelights To eliminate the possibility of safelight illumination affecting the sensitometric results, all films shall be handled in complete darkness during sample preparation, exposing and processing. 5.3 Exposure 5.3.1 Sample condition D
34、uring exposure, the samples shall be equilibrated with air at a temperature of 23 C 2 C and 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 fil
35、m type being exposed shall conform to the specification given in ISO 7589. 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, the illuminant should be specif
36、ied in the instructions. ISO speed shall be specified for use without a filter in front of the camera lens. If a 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
37、the 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 from 400 nm to 700 nm shall not exceed 5 % of the average density obtained over the same interval or
38、 0,03 density, whichever is greater. In the interval from 360 nm to 400 nm, 10 % of this same average density, or 0,06 density, whichever is greater, is acceptable. If a stepped increment modulation is used, the exposure increment shall not be greater than 0,15 log10H. The width and length of a sing
39、le step shall be adequate to obtain a uniform density within the reading aperture specified for densitometry. If a continuous variable modulator is used, the change in exposure with distance along the test strip shall be uniform and not greater than 0,04 log10H per millimetre. 5.3.5 Exposure time Th
40、e exposure time shall be between 5 s and 1/1 000 s corresponding to the usage practice for the particular film tested. Since the speed of film is dependent on exposure time because of reciprocity law failure, the exposure time used for determining ISO speed should be specified in the instructions fo
41、r use. 5.4 Processing 5.4.1 Conditioning of samples In the time interval between exposure and processing, the samples shall be equilibrated with air at 23 C 2 C and a relative humidity of (50 5) %. The processing shall be completed in not fewer than 5 days and not more than 10 days after exposure fo
42、r general-purpose films, and not fewer than 4 h and not more than 7 days for professional films. Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 12:39:14 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ISO 2240:1994(E) BSI 01-20003 5.4.2 Processing specifications No processing specifications are d
43、escribed in this International Standard in recognition of the wide range of chemicals and equipment used. ISO speed provided by film manufacturers generally applies to the film when it is processed in accordance with their recommendations to produce the photographic characteristics specified for the
44、 process. Process information shall be available from film manufacturers or others who quote ISO speed. This shall specify the chemicals, time, temperatures, agitation and procedure used for each of the processing steps and any additional information required sensitometric results described. The val
45、ues for speed obtained using various processing procedures can differ significantly. Although different speeds for a particular film can be achieved by varying the process, the user should be aware that other sensitometric and physical changes can also accompany the speed changes. 5.5 Densitometry I
46、SO standard visual diffuse transmission density of the processed images shall be measured using a densitometer complying with the geometric conditions specified in ISO 5-2 and the spectral conditions specified in ISO 5-3. These conditions are designated: DT (90opal; SH: u 10; VT) or DT (u 10; SH: 90
47、 opal; VT) Readings shall be taken in a uniform area of the image. 5.6 Evaluation 5.6.1 Sensitometric curve The ISO standard visual diffuse transmission density values are plotted against the logarithm to the base 10 of the corresponding exposures (H) expressed in lux seconds, to obtain a sensitomet
48、ric curve similar to that illustrated in Figure 1. Figure 1 Sensitometric curve Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 12:39:14 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ISO 2240:1994(E) 4 BSI 01-2000 5.6.2 Minimum density The minimum density shall be determined from a film sample a
49、dequately exposed to produce the minimum density possible and processed simultaneously with the sample exposed for determining the sensitometric curve. 5.6.3 Determination of Hm and log10 Hm The method for determining ISO speed is illustrated in Figure 1. Point T is located on the sensitometric curve at the density of 0,20 above the minimum density. Point S is then located on the curve 2,00 above the minimum density to bracket the normal range of density in a typical transparency. In order to represent a reasonable reproduction of
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