BS ISO 9848-2004 Photography - Source document microfilms - Determination of ISO speed and ISO average gradient《摄影 源文件缩微胶片 ISO感光速度和ISO平均梯度的测定》.pdf

《BS ISO 9848-2004 Photography - Source document microfilms - Determination of ISO speed and ISO average gradient《摄影 源文件缩微胶片 ISO感光速度和ISO平均梯度的测定》.pdf》由会员分享，可在线阅读，更多相关《BS ISO 9848-2004 Photography - Source document microfilms - Determination of ISO speed and ISO average gradient《摄影 源文件缩微胶片 ISO感光速度和ISO平均梯度的测定》.pdf（18页珍藏版）》请在麦多课文档分享上搜索。

1、BRITISH STANDARD BS ISO 9848:2003 Photography Source document microfilms Determination of ISO speed and ISO average gradient ICS 37.040.20; 37.080 BS ISO 9848:2003 This British Standard was published under the authority of the Standards Policy and Strategy Committee on 5 April 2004 BSI 5 April 2004

2、ISBN 0 580 43596 2 National foreword This British Standard reproduces verbatim ISO 9848:2003 and 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: A list of organizations repre

3、sented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international publications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by usin

4、g the “Search” 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 fr

5、om legal obligations. aid enquirers 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

6、 UK. Summary of pages This document comprises a front cover, an inside front cover, the ISO title page, pages ii to v, a blank page, pages 1 to 9 and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued. Amendments issued since publication Amd

7、. No. Date Comments Reference number ISO 9848:2003(E)INTERNATIONAL STANDARD ISO 9848 Second edition 2003-12-01 Photography Source document microfilms Determination of ISO speed and ISO average gradient Photographie Microfilms de prises de vue Dtermination de la sensibilit ISO et du contraste moyen I

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13、tions. 1 4 Sampling and storage. 2 5 Test method. 2 5.1 Principle . 2 5.2 Safelights . 2 5.3 Exposure 2 5.4 Processing. 4 5.5 Densitometry . 4 5.6 Evaluation 4 6 Product classification. 5 6.1 ISO speed. 5 6.2 ISO average gradient 5 6.3 Accuracy 7 7 Product marking and labelling. 7 7.1 Speed 7 7.2 Av

14、erage gradient. 7 7.3 General. 7 Annex A (informative) Use of ISO speed values 8 Bibliography . 9 BSISO9848:2003iv Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standar

15、ds 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. International organizations, governmental and non-governmental, in liaison with ISO, also take

16、 part in the work. ISO collaborates closely with 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, Part 2. The main task of technical committees is

17、to prepare International Standards. 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. Attention is drawn to the possibility

18、 that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 9848 was prepared by Technical Committee ISO/TC 42, Photography. This second edition cancels and replaces the first edition (ISO 9848:

19、1993), which has been technically revised. BSISO9848:2003 vIntroduction This International Standard describes the method for determining the ISO speed and ISO average gradient of camera negative microfilms exposed with an incandescent tungsten source at a distribution temperature of 2 650 K 100 K (t

20、o simulate “undervolted” photoflood). The ISO speed and ISO average gradient determined by applying this International Standard are for film/process systems, not just the film alone. The sensitometric characteristics of microfilm are dependent on the process conditions (developer, time, temperature,

21、 agitation, etc.) and some films will provide satisfactory results only in specific processes. Therefore, process conditions are not specified in this International Standard. They should be specified when the sensitometric values are quoted in manufacturers literature to enable proper interpretation

22、. Because of “reciprocity law failure”, it is desirable to specify the exposure time used when quoting ISO speed and ISO average gradient values to ensure proper interpretation. Source document microfilming cameras do not have a “standard” exposure time. The exposure time used in evaluating the sens

23、itometric characteristics of the film should be the same as that for which the film is intended to be used. The alternative of using only one exposure time in this International Standard could be misleading if the film produces other results at its “end use” exposure time. If the film is used in a v

24、ariety of applications, speed and contrast values at a range of exposure times may be helpful to the user. Typical light sources for microfilms include tungsten, xenon and fluorescent. Since xenon and fluorescent sources are not yet standardized they are not included in this International Standard,

25、but will be incorporated in the document when standardized. Due to spectral output differences, ISO values determined by using tungsten sensitometric exposure cannot be used for applications where fluorescent or xenon illumination are used. The effective density of film images depends on the geometr

26、y of the optical system in which they are used. Many source document microfilms are used as “masters” for producing copies by contact printing, thereby requiring diffuse density measurements. When film is viewed on a microfilm “reader”, projection densitometry is more appropriate. Since the more cri

27、tical end use is the former, this International Standard specifies diffuse density. Spectral conditions of the density measurement must also be specified. Printing density characteristics are dependent upon the spectral sensitivity of the print film chosen for use as well as the spectral energy dist

28、ribution of the printing light source. These parameters are determined by “end use” system requirements. Since no standard printing conditions have been agreed to or defined in this document, the use of printing density is precluded and visual density measurements will, therefore, be used as a compr

29、omise. The speed point density (1,20 above minimum density) was selected as a compromise of the proper image background densities. Since microfilms have medium to high average gradients, exposure latitude is rather narrow. Thus, the speed value should be considered “approximate” and used only as a g

30、uide for initial testing. For critical work, the final exposure should be determined by testing the film over a range of exposures and the optimum chosen. A measurement of contrast is provided by the average gradient which relates the line density to the background density. This measurement correlat

31、es with the visual appearance of the recorded image and should aid users in selecting the best film for their application. This International Standard is concerned primarily with the evaluation of a few characteristics of source document microfilms that are especially important in using the product.

32、 Therefore, the test method, sensitometric criteria and sampling procedures can prove inadequate for controlling quality in a film manufacturing operation. Since speed and contrast vary greatly depending on exposure time, illuminant quality and process conditions, it is important for the user to con

33、sult the film manufacturer regarding the film and sensitometric characteristics that fit their application. BSISO9848:2003BSISO9848:2003INTENRATIONAL TSANDADR IS:8489 O3002(E)I SO 3002 All irhgts seredevr 1Photography Source document microfilms Determination of ISO speed and ISO average gradient 1 S

34、cope This International Standard specifies a method for determining the ISO speed and ISO average gradient of black-and-white camera negative photographic films used for first generation microfilming of source documents at exposure times typically found with tungsten sources. These source documents

35、include any handwritten or printed alphanumeric and line documents such as books, periodicals, business correspondence, and engineering drawings. The value-rating system described in this International Standard is only useful to the consumer if his exposure illumination is from an incandescent tungs

36、ten source as described in 5.3.3. It is not intended to include pictorial or continuous tone reproduction, computer output microfilm (COM), reversal processed or direct positive films or other films exposed by non-tungsten sources such as laser or cathode ray tube. The ISO speed and ISO average grad

37、ient values obtained by applying this International Standard are intended for practical use in comparing film/process combinations and for computing exposures. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only

38、 the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 5-2, Photography Density measurements Part 2: Geometric conditions for transmission density ISO 5-3, Photography Density measurements Part 3: Spectral conditions

39、ISO 554, Standard atmospheres for conditioning and/or testing Specifications ISO 6728, Photography Camera lenses Determination of ISO colour contribution index (ISO/CCI) 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 speed quantitative measu

40、re of the response of the photographic material to radiant energy for the specified conditions of exposure, processing, density measurement and analysis 3.2 exposure H time integral of illuminance measured on the plane of the film surface NOTE 1 In the International lighting vocabulary 3 , H is defi

41、ned as the luminous exposure. In this International Standard, “luminous exposure” is simply referred to as “exposure”. BSISO9848:20032 NOTE 2 Exposure is measured in lux seconds. NOTE 3 Exposure is often expressed in log 10 H units. 3.3 average gradient G slope of a line drawn between two specified

42、points on the sensitometric curve 3.4 minimum density D minminimum density value obtainable from an unexposed sample of the same product processed simultaneously with the sample exposed for determining the sensitometric curve 4 Sampling and storage In determining the ISO speed and ISO average gradie

43、nt of a product, it is important that the samples evaluated yield the average results obtained by users. This requires evaluating several different batches periodically under the conditions specified in this International Standard. Prior to evaluation, the samples shall be stored according to the ma

44、nufacturers 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 the proper calibration of equipment and processes. The basic objective in selecting and storing samples as described above is to

45、 ensure the film characteristics are representative of those obtained by a user at the time of use. 5 Test method 5.1 Principle Samples are exposed and processed as specified in 5.3 and 5.4, respectively. Density measurements are obtained from the resultant images to produce a sensitometric curve fr

46、om which values are taken and used to determine ISO speed and ISO average gradient. See Figure 1. 5.2 Safelights To eliminate the possibility of safelight illumination affecting the sensitometric results, all films shall be handled in complete darkness during sensitometric exposing and processing. 5

47、.3 Exposure 5.3.1 Sampling conditions During exposure, the samples shall be at a temperature of 23 C 2 C and a relative humidity of (50 5) %. See ISO 554. 5.3.2 Type of sensitometer The sensitometer shall be a non-intermittent, illuminance-scale type. BSISO9848:2003I SO 3002 All irhgts seredevr 3Key

48、 X log 10 H, lux seconds Y ISO standard visual diffuse transmission density 1 average gradient 2 minimum density Figure 1 Sensitometric curve 5.3.3 Radiant energy quality ISO speed shall be determined using an incandescent tungsten source at a distribution temperature of 2 650 K 100 K (to simulate “

49、undervolted” photoflood) as modified by the spectral transmittance of the standard camera lens as described in ISO 6728. Speed and average gradient determined for other illuminants will be different. ISO speed shall be specified for use without a filter in front of the camera lens. If film is used with colour filtration in front of the camera lens, an “equivalent” speed number can be used to determine the exposure of the film with that filt