1、 g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58films and paper prints Methods for measuring image stabilityICS 37.040.20Photography Processed phot
2、ographic colour BRITISH STANDARDBS ISO 18909:2006BS ISO 18909:2006This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 March 2007 BSI 2007ISBN 978 0 580 50314 6Amendments issued since publicationAmd. No. Date Commentssecretary.This publication
3、does not purport to include 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.National forewordThis British Standard was published by BSI. It is the UK implementation of ISO 1
4、8909:2006, incorporating corrigendum December 2006.The start and finish of text introduced or altered by ISO corrigendum December 2006 is indicated in the text by tags .The UK participation in its preparation was entrusted to Technical Committee CPW/42, Photography.A list of organizations represente
5、d on CPW/42 can be obtained on request to its Reference numberISO 18909:2006(E)INTERNATIONAL STANDARD ISO18909First edition2006-07-15Photography Processed photographic colour films and paper prints Methods for measuring image stability Photographie Films et papiers photographiques couleur traits Mth
6、odes de mesure de la stabilit de limage BS ISO 18909:2006ii iiiContents 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 b
7、e measured . 3 3.6 Method of correction of density measurements for dminchanges . 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
8、 . 10 4.3 Number of specimens 11 4.4 Test equipment and operation 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
9、 in moisture-proof bags 12 4.8 Computation of dark stability 12 5 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 sta
10、ndard window glass.14 5.6 High-intensity filtered xenon arc ID65 illuminant (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 illuminati
11、on 3,0 klx CIE illuminant A spectral distribution 18 5.9 Simulated 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 st
12、ability tests 23 6.3 Light stability tests . 24 Annex A (informative) 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 dmincorrection of reflection print materials 28 A
13、nnex D (informative) Illustration of Arrhenius calculation for dark stability . 33 BS ISO 18909:2006iv Annex 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-
14、stability tests with prints framed under glass or plastic sheets. 39 Annex G (informative) Data treatment for the stability of light-exposed colour images. 41 Bibliography . 49 BS ISO 18909:2006vForeword ISO (the International Organization for Standardization) is a worldwide federation of national s
15、tandards 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
16、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 standardization. International Standards are drafted in accordance with the rules gi
17、ven in 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
18、 75 % 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, P
19、hotography. This first edition cancels and replaces ISO 10977:1993, of which it constitutes a technical revision. BS ISO 18909:2006vi Introduction This International Standard is one of a series of standards dealing with the physical properties and stability of imaging materials. To facilitate identi
20、fication 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 photographic images; the second c
21、overs 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 colour photographic materia
22、ls. 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. Knowledge of the useful life o
23、f 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 under various storage
24、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 colour photographs. Colou
25、r 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 occur, such as embrittle
26、ment 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 quality of chemical process
27、ing 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 temperature and relative humidi
28、ty 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 hand, can greatly prol
29、ong 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 distribution of the ill
30、umination, 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 image quality). Ultrav
31、iolet (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 displayed under varying co
32、mbinations 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 in advance. Furthermore,
33、 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 of fading or staining,
34、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 twice as wide BS ISO 18909:2
35、006viifor 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 can be helpful in assessing the visual changes that o
36、ccur 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, most modern colour films and papers have images that f
37、ade 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 assess in a relatively short time the probable long-term
38、 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 humidity levels. Similarly, information about the lig
39、ht 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 produce the desired amount of image fading (or staining
40、). 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 of normal use. Accelerated light stability tests for pr
41、edicting 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 dyes to fade, or to form stain. This even applies when
42、 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 fading and stain formation can be greater or smaller under a
43、ccelerated 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 surrounding atmosphere into a photographs image-containing
44、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 content of the test specimen also influence the magnitude of
45、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 stain level can be reasonably estimated only for condition
46、s 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 stability of different types of photographic colour films
47、 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) colour reversal film with incorporated oil-soluble couplers;
48、 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; BS IS
49、O 18909:2006viii i) colour dye imbibition (dye transfer) prints; j) integral colour instant print film with dye developers; k) peel-apart colour instant print film with dye developers; l) integral colour instant print film with dye releasers. The results of extensive tests with these materials showed that the methods and procedures of this International Standard can be used to obtain meaningful information about the long-term dark stability and the light stability of colour photographs made with a specific product. Th
