1、 Reference number ISO 18909:2006(E) ISO 2006INTERNATIONAL STANDARD ISO 18909 First edition 2006-07-15 Photography Processed photographic colour films and paper prints Methods for measuring image stability Photographie Films et papiers photographiques couleur traits Mthodes de mesure de la stabilit d
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5、address given below. ISO 2006 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or
6、ISOs member body in the country of the requester. ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ii ISO 2006 All rights reservedISO 18909:2006(E) ISO 2006 All rights reserved iiiCont
7、ents Page Foreword. v Introduction . vi 1 Scope . 1 2 Normative references . 1 3 Test methods General . 1 3.1 Sensitometric exposure . 1 3.2 Processing. 2 3.3 Densitometry . 3 3.4 Definition of density terms 3 3.5 Density values to be measured . 3 3.6 Method of correction of density measurements for
8、 d minchanges . 3 3.7 Computation of image-life parameters. 8 3.8 Effects of dye fading and stain formation on the printing quality of colour negative images 9 4 Test methods Dark stability 10 4.1 Introduction . 10 4.2 Test conditions . 10 4.3 Number of specimens 11 4.4 Test equipment and operation
9、for specimens free-hanging in air 11 4.5 Test equipment and operation for specimens sealed in moisture-proof bags 12 4.6 Conditioning and packaging of specimens in moisture-proof bags. 12 4.7 Incubation conditions for specimens sealed in moisture-proof bags 12 4.8 Computation of dark stability 12 5
10、Test methods Light stability . 12 5.1 Introduction . 12 5.2 Number of specimens 13 5.3 Irradiance measurements and normalization of test results 13 5.4 Backing of test specimens during irradiation testing. 13 5.5 Specification for standard window glass.14 5.6 High-intensity filtered xenon arc ID65 i
11、lluminant (50 klx to 100 klx) for simulated indoor indirect daylight through window glass. 14 5.7 Glass-filtered fluorescent room illumination Cool White fluorescent lamps (80 klx or lower) 16 5.8 Incandescent tungsten room illumination 3,0 klx CIE illuminant A spectral distribution 18 5.9 Simulated
12、 outdoor sunlight (xenon arc) 100 klx CIE D65 spectral distribution 18 5.10 Intermittent tungsten-halogen lamp slide projection 1 000 klx . 21 5.11 Computation of light stability 21 6 Test report . 21 6.1 Introduction . 21 6.2 Dark stability tests 23 6.3 Light stability tests . 24 Annex A (informati
13、ve) Numbering system for related International Standards. 25 Annex B (informative) A method of interpolation for step wedge exposures 27 Annex C (informative) Method for power equation d mincorrection of reflection print materials 28 Annex D (informative) Illustration of Arrhenius calculation for da
14、rk stability . 33 ISO 18909:2006(E) iv ISO 2006 All rights reservedAnnex E (informative) The importance of the starting density in the assessment of dye fading and colour balance changes in light-stability tests 37 Annex F (informative) Enclosure effects in light-stability tests with prints framed u
15、nder glass or plastic sheets. 39 Annex G (informative) Data treatment for the stability of light-exposed colour images. 41 Bibliography . 49 ISO 18909:2006(E) ISO 2006 All rights reserved vForeword ISO (the International Organization for Standardization) is a worldwide federation of national standar
16、ds 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. International organi
17、zations, 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 standardization. International Standards are drafted in accordance with the rules given in
18、 the ISO/IEC Directives, Part 2. The main task of technical committees is 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 %
19、of the member bodies casting a vote. Attention is drawn to the possibility 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 18909 was prepared by Technical Committee ISO/TC 42, Photogr
20、aphy. This first edition cancels and replaces ISO 10977:1993, of which it constitutes a technical revision. ISO 18909:2006(E) vi ISO 2006 All rights reservedIntroduction This International Standard is one of a series of standards dealing with the physical properties and stability of imaging material
21、s. To facilitate identification of these documents, they are assigned a number within the block from 18900 18999 (see Annex A). This International Standard is divided into two parts. The first covers the methods and procedures for predicting the long-term, dark storage stability of colour photograph
22、ic images; the second covers the methods and procedures for measuring the colour stability of such images when exposed to light of specified intensities and spectral distribution, at specified temperatures and relative humidities. Today, the majority of continuous-tone photographs are made with colo
23、ur photographic materials. The length of time that such photographs are to be kept can vary from a few days to many hundreds of years and the importance of image stability can be correspondingly small or great. Often the ultimate use of a particular photograph may not be known at the outset. Knowled
24、ge of the useful life of colour photographs is important to many users, especially since stability requirements often vary depending upon the application. For museums, archives, and others responsible for the care of colour photographic materials, an understanding of the behaviour of these materials
25、 under various storage and display conditions is essential if they are to be preserved in good condition for long periods of time. Organic cyan, magenta and yellow dyes that are dispersed in transparent binder layers coated on to transparent or white opaque supports form the images of most modern co
26、lour photographs. Colour photographic dye images typically fade during storage and display; they will usually also change in colour balance because the three image dyes seldom fade at the same rate. In addition, a yellowish (or occasionally other colour) stain may form and physical degradation may o
27、ccur, such as embrittlement and cracking of the support and image layers. The rate of fading and staining can vary appreciably and is governed principally by the intrinsic stability of the colour photographic material and by the conditions under which the photograph is stored and displayed. The qual
28、ity of chemical processing is another important factor. Post-processing treatments, such as application of lacquers, plastic laminates and retouching colours, may also affect the stability of colour materials. The two main factors that influence storage behaviour, or dark stability, are the temperat
29、ure and relative humidity of the air that has access to the photograph. High temperature, particularly in combination with high relative humidity, will accelerate the chemical reactions that can lead to degradation of one or more of the image dyes. Low-temperature, low-humidity storage, on the other
30、 hand, can greatly prolong the life of photographic colour images. Other potential causes of image degradation are atmospheric pollutants (such as oxidizing and reducing gases), micro-organisms and insects. Primarily the intensity of the illumination, the duration of exposure to light, the spectral
31、distribution of the illumination, and the ambient environmental conditions influence the stability of colour photographs when displayed indoors or outdoors. (However, the normally slower dark fading and staining reactions also proceed during display periods and will contribute to the total change in
32、 image quality). Ultraviolet (UV) radiation is particularly harmful to some types of colour photographs and can cause rapid fading as well as degradation of plastic layers such as the pigmented polyethylene layer of resin-coated (RC) paper supports. In practice, colour photographs are stored and dis
33、played under varying combinations of temperature, relative humidity and illumination, and for different lengths of time. For this reason, it is not possible to precisely predict the useful life of a given type of photographic material unless the specific conditions of storage and display are known i
34、n advance. Furthermore, the amount of change that is acceptable differs greatly from viewer to viewer and is influenced by the type of scene and the tonal and colour qualities of the image. After extensive examination of amateur and professional colour photographs that have suffered varying degrees
35、of fading or staining, no consensus has been achieved on how much change is acceptable for various image quality criteria. For this reason, this International Standard does not specify acceptable end- points for fading and changes in colour balance. Generally, however, the acceptable limits are twic
36、e as wide ISO 18909:2006(E) ISO 2006 All rights reserved viifor changes in overall image density as for changes in colour balance. For this reason, different criteria have been used as examples in this International Standard for predicting changes in image density and colour balance. Pictorial tests
37、 can be helpful in assessing the visual changes that occur in light and dark stability tests, but are not included in this International Standard because no single scene is representative of the wide variety of scenes actually encountered in photography. In dark storage at normal room temperatures,
38、most modern colour films and papers have images that fade and stain too slowly to allow evaluation of the dark storage stability simply by measuring changes in the specimens over time. In such cases, too many years would be required to obtain meaningful stability data. It is possible, however, to as
39、sess in a relatively short time the probable long-term fading and staining behaviour at moderate or low temperatures by means of accelerated ageing tests carried out at high temperatures. The influence of relative humidity also can be evaluated by conducting the high-temperature tests at two or more
40、 humidity levels. Similarly, information about the light stability of colour photographs can be obtained from accelerated light- stability tests. These require special test units equipped with high-intensity light sources in which test strips can be exposed for days, weeks, months or even years, to
41、produce the desired amount of image fading (or staining). The temperature of the specimens and their moisture content must be controlled throughout the test period, and the types of light sources must be chosen to yield data that can be correlated satisfactorily with those obtained under conditions
42、of normal use. Accelerated light stability tests for predicting the behaviour of photographic colour images under normal display conditions may be complicated by reciprocity failure. When applied to light-induced fading and staining of colour images, reciprocity failure refers to the failure of many
43、 dyes to fade, or to form stain. This even applies when dyes are irradiated with high-intensity versus low-intensity light, even though the total light exposure (intensity time) is kept constant through appropriate adjustments in exposure duration (see 1 in the Bibliography). The extent of dye fadin
44、g and stain formation can be greater or smaller under accelerated conditions, depending on the photochemical reactions involved in the dye degradation, the kind of dye dispersion, the nature of the binder material, and other variables. For example, the supply of oxygen that can diffuse from the surr
45、ounding atmosphere into a photographs image-containing emulsion layers may be restricted in an accelerated test (dry gelatin is an excellent oxygen barrier). This may change the rate of dye- fading relative to that which would occur under normal display conditions. The temperature and moisture conte
46、nt of the test specimen also influence the magnitude of reciprocity failure. Furthermore, light fading is influenced by the pattern of irradiation (continuous versus intermittent) as well as by light/dark cycling rates. For all these reasons, long-term changes in image density, colour balance and st
47、ain level can be reasonably estimated only for conditions similar to those employed in the accelerated tests, or when good correlation has been confirmed between accelerated tests and actual conditions of use. In order to establish the validity of the test methods for evaluating the dark and light s
48、tability of different types of photographic colour films and papers, the following product types were selected for the tests: a) colour negative film with incorporated oil-soluble couplers; b) colour negative motion picture pre-print and negative films with incorporated oil-soluble couplers; c) colo
49、ur reversal film with incorporated oil-soluble couplers; d) colour reversal film with incorporated Fischer-type couplers; e) colour reversal film with couplers in the developers; f) silver dye-bleach film and prints; g) colour prints with incorporated oil-soluble couplers; h) colour motion picture print films with incorporated oil-soluble couplers; ISO 18909:2006(E) viii ISO 2006 All rights reservedi) colour dye imbibition (dye transfer) prints; j) integral colour instant print film with dye developers; k) peel-apart colour i
