ISO-10526-2007

Reference number ISO 10526:2007(E) CIE S 014-2/E:2006 © ISO 2007 INTERNATIONAL STANDARD ISO 10526 CIE S 014-2/E First edition 2007-10-15 CIE standard illuminants for colorimetry Illuminants colorimétriques normalisés CIE Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=IHS Employees/1111111001, User=leee, leee Not for Resale, 11/22/2007 18:44:35 MSTNo reproduction or networking permitted without license from IHS - - ` , ` ` ` , ` ` , ` , , ` , ` , ` , , ` ` , ` ` , ` , ` , - ` - ` , , ` , , ` , ` , , ` - - - ISO 10526:2007(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat accepts no liability in this area. Adobe is a trademark of Adobe Systems Incorporated. Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below. COPYRIGHT PROTECTED DOCUMENT © ISO 2007 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 ISO's 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 copyright@iso.org Web www.iso.org Published in Switzerland ii © ISO 2007 — All rights reserved Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=IHS Employees/1111111001, User=leee, leee Not for Resale, 11/22/2007 18:44:35 MSTNo reproduction or networking permitted without license from IHS - - ` , ` ` ` , ` ` , ` , , ` , ` , ` , , ` ` , ` ` , ` , ` , - ` - ` , , ` , , ` , ` , , ` - - - ISO 10526:2007(E) © ISO 2007 — All rights reserved iii ISO (the International 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 established 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 standardization. ISO 10526 was prepared as Standard CIE S 014-2/E by the International Commission on Illumination, which has been recognized by the ISO Council as an international standardizing body. It was adopted by ISO under a special procedure which requires approval by at least 75 % of the member bodes casting a vote, and is published as a joint ISO/CIE edition. The International Commission on Illumination (abbreviated as CIE from its French title) is an organization devoted to international cooperation and exchange of information among its member countries on all matters relating to the science and art of lighting. International Standard ISO 10526 was prepared by CIE Technical Committee 2-33 Reformulation of CIE Standard Illuminants A and D65. Foreword ISO 10526 cancels and replaces ISO/CIE 10526:1999. The numerical values of the relative spectral distributions of standard illuminants A and D65 defined by this Standard are the same, within an accuracy of six significant digits, as those defined in earlier versions of these illuminants. Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=IHS Employees/1111111001, User=leee, leee Not for Resale, 11/22/2007 18:44:35 MSTNo reproduction or networking permitted without license from IHS --`,```,``,`,,`,`,`,,``,``,`,`,-`-`,,`,,`,`,,`--- Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=IHS Employees/1111111001, User=leee, leee Not for Resale, 11/22/2007 18:44:35 MSTNo reproduction or networking permitted without license from IHS - - ` , ` ` ` , ` ` , ` , , ` , ` , ` , , ` ` , ` ` , ` , ` , - ` - ` , , ` , , ` , ` , , ` - - - Standard CIE S 014-2/E:2006 Colorimetry - Part 2: CIE Standard Illuminants Colorimétrie - Partie 2: Illuminants normalisés CIE Farbmessung - Teil 2: CIE Normlichtarten CIE Standards are copyrighted and shall not be reproduced in any form, entirely or partly, without the explicit agreement of the CIE. CIE Central Bureau, Vienna CIE S 014-2/E:2006 Kegelgasse 27, A-1030 Vienna, Austria UDC: 535.65:006 Descriptor: Standardisation of colour measurement 535.643.2 Standard colorimetric system ISO 10526:2007(E) CIE S 014-2/E:2006 © CIE 2006 — All rights reserved © ISO 2007 — All rights reserved v Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=IHS Employees/1111111001, User=leee, leee Not for Resale, 11/22/2007 18:44:35 MSTNo reproduction or networking permitted without license from IHS - - ` , ` ` ` , ` ` , ` , , ` , ` , ` , , ` ` , ` ` , ` , ` , - ` - ` , , ` , , ` , ` , , ` - - - © CIE, 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 CIE Central Bureau at the address below. CIE Central Bureau Kegelgasse 27 A-1030 Vienna Austria Tel.: +43 1 714 3187 0 Fax: +43 1 714 3187 18 e-mail: ciecb@ping.at Web: www.cie.co.at/ ISO 10526:2007(E) CIE S 014-2/E:2006 © CIE 2006 — All rights reserved © ISO 2007 — All rights reserved vi Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=IHS Employees/1111111001, User=leee, leee Not for Resale, 11/22/2007 18:44:35 MSTNo reproduction or networking permitted without license from IHS - - ` , ` ` ` , ` ` , ` , , ` , ` , ` , , ` ` , ` ` , ` , ` , - ` - ` , , ` , , ` , ` , , ` - - - ISO 10526:2007(E) CIE S 014-2/E:2006 © CIE 2006 — All rights reserved © ISO 2007 — All rights reserved vii FOREWORD Standards produced by the Commission Internationale de l’Eclairage (CIE) are a concise documentation of data defining aspects of light and lighting, for which international harmony requires such unique definition. CIE Standards are therefore a primary source of internationally accepted and agreed data, which can be taken, essentially unaltered, into universal standard systems. This CIE Standard replaces ISO 10526:1999/CIE S005:1998 and was approved by the CIE Board of Administration and the National Committees of the CIE. It contains only minor changes from the previous standard, which was prepared by CIE Technical Committee 2-33, "Reformulation of CIE Standard Illuminants A and D65" *). The numerical values of the relative spectral distributions of standard illuminants A and D65 defined by this Standard are the same, within an accuracy of six significant digits, as those defined in earlier versions of these illuminants. TABLE OF CONTENTS FOREWORD ............................................................................................................................vii 1. SCOPE .................................................................................................................................. 1 2. NORMATIVE REFERENCES................................................................................................ 2 3. DEFINITIONS........................................................................................................................ 2 4. CIE STANDARD ILLUMINANT A.......................................................................................... 4 4.1 Definition .......................................................................................................................... 4 4.2 Theoretical basis.............................................................................................................. 4 4.3 Supplementary notes ....................................................................................................... 4 5. CIE STANDARD ILLUMINANT D65...................................................................................... 5 5.1 Definition .......................................................................................................................... 5 5.2 Experimental basis........................................................................................................... 5 5.3 Correlated colour temperature......................................................................................... 5 6. CIE SOURCES FOR PRODUCING CIE STANDARD ILLUMINANTS................................. 5 6.1 CIE source A.................................................................................................................... 5 6.2 Source for CIE standard illuminant D65 .......................................................................... 6 TABLE 1. RELATIVE SPECTRAL POWER DISTRIBUTIONS OF CIE STANDARD ILLUMINANTS A AND D65 (wavelengths in standard air). .................................................. 7 ANNEX: BIBLIOGRAPHY (INFORMATIVE) ............................................................................. 7 *) Chairman of this TC was K. D. Mielenz (US), members were: J. J. Hsia (US), J. R. Moore (GB), A. R. Robertson (CA), H. Terstiege (DE) �, J. F. Verrill (GB) �. This present revision was finalized by an editorial group in CIE Division 2: J. Gardner (AU), T. Goodman (UK), K. Mielenz (US), J. Moore (UK), Y. Ohno (US), A. Robertson (CA), J. Schanda (HU). © CIE, 2006 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=IHS Employees/1111111001, User=leee, leee Not for Resale, 11/22/2007 18:44:35 MSTNo reproduction or networking permitted without license from IHS - - ` , ` ` ` , ` ` , ` , , ` , ` , ` , , ` ` , ` ` , ` , ` , - ` - ` , , ` , , ` , ` , , ` - - - Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=IHS Employees/1111111001, User=leee, leee Not for Resale, 11/22/2007 18:44:35 MSTNo reproduction or networking permitted without license from IHS --`,```,``,`,,`,`,`,,``,``,`,`,-`-`,,`,,`,`,,`--- COLORIMETRY - PART 2: CIE STANDARD ILLUMINANTS 1. SCOPE This International Standard specifies two illuminants for use in colorimetry. The illuminants, which are defined in clauses 4 and 5 of this International Standard, are as follows: a) CIE standard illuminant A This is intended to represent typical, domestic, tungsten-filament lighting. Its relative spectral power distribution is that of a Planckian radiator at a temperature of approximately 2 856 K. CIE standard illuminant A should be used in all applications of colorimetry involving the use of incandescent lighting, unless there are specific reasons for using a different illuminant. b) CIE standard illuminant D65 This is intended to represent average daylight and has a correlated colour temperature of approximately 6 500 K. CIE standard illuminant D65 should be used in all colorimetric calculations requiring representative daylight, unless there are specific reasons for using a different illuminant. Variations in the relative spectral power distribution of daylight are known to occur, particularly in the ultraviolet spectral region, as a function of season, time of day, and geographic location. However, CIE standard illuminant D65 should be used pending the availability of additional information on these variations. Values for the relative spectral power distribution of CIE standard illuminants A and D65 are given in Table 1 of this International Standard. Values are given at 1 nm intervals from 300 nm to 830 nm. The term "illuminant" refers to a defined spectral power distribution, not necessarily realizable or provided by an artificial source. Illuminants are used in colorimetry to compute the tristimulus values of reflected or transmitted object colours under specified conditions of illumination. The CIE has also defined illuminant C and other illuminants D. These illuminants are described in Publication CIE 15:2004 but they do not have the status of primary CIE standards accorded to the CIE standard illuminants A and D65 described in this International Standard. It is recommended that one of the two CIE standard illuminants defined in this International Standard be used wherever possible. This will greatly facilitate the comparison of published results. It is noted that in the fields of graphic arts and photography extensive use is also made of CIE illuminant D50. In most practical applications of colorimetry, it is sufficient to use the values of CIE standard illuminants A and D65 at less frequent wavelength intervals or in a narrower spectral region than defined in this Standard. Data and guidelines that facilitate such practice are provided in Publication CIE 15:2004, together with other recommended procedures for practical colorimetry. The term "source" refers to a physical emitter of light, such as a lamp or the sky. In certain cases, the CIE recommends laboratory sources that approximate the spectral power distributions of CIE illuminants. In all cases, however, the definition of a CIE recommended source is secondary to the definition of the corresponding CIE illuminant, because of the possibility that, from time to time, new developments will lead to improved sources that represent a particular illuminant more accurately or are more suitable for laboratory use. Subclause 6.1 of this International Standard describes CIE source A, which is recommended for laboratory realizations of CIE standard illuminant A. At present, there is no CIE recommended source representing CIE standard illuminant D65. ISO 10526:2007(E) CIE S 014-2/E:2006 © CIE 2006 — All rights reserved © ISO 2007 — All rights reserved 1 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=IHS Employees/1111111001, User=leee, leee Not for Resale, 11/22/2007 18:44:35 MSTNo reproduction or networking permitted without license from IHS - - ` , ` ` ` , ` ` , ` , , ` , ` , ` , , ` ` , ` ` , ` , ` , - ` - ` , , ` , , ` , ` , , ` - - - 2. NORMATIVE REFERENCES The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. CIE 15:2004. Colorimetry, 3 rd edition. CIE 17.4-1987. International Lighting Vocabulary (ILV) - Joint publication IEC/CIE. ISO 23603:2005/CIE S 012/E:2004. Standard method of assessing the spectral quality of daylight simulators for visual appraisal and measurement of colour. CIE S 014-1/E:2006. Colorimetry Part 1: CIE standard colorimetric observers. 3. DEFINITIONS For the purposes of this International Standard, the following definitions apply. These definitions are taken from CIE 17.4-1987, where other relevant terms will also be found. 3.1 chromaticity coordinates (see ILV 845-03-33) ratio of each of a set of three tristimulus values to their sum NOTE 1: As the sum of the three chromaticity coordinates equals 1, two of them are sufficient to define a chromaticity. NOTE 2: In the CIE 1931 and 1964 standard colorimetric systems, the chromaticity co- ordinates are represented by the symbols x, y, z and x 10 , y 10 , z 10 . 3.2 chromaticity diagram (see ILV 845-03-35) plane diagram in which points specified by chromaticity co-ordinates represent the chromaticities of colour stimuli 3.3 CIE standard illuminants illuminants A and D65 defined by the CIE in terms of relative spectral power distributions 1 3.4 CIE sources artificial sources, specified by the CIE, whose relative spectral power distributions are approximately the same as those of CIE standard illuminants 1 3.5 CIE 1976 uniform chromaticity scale diagram; CIE 1976 UCS diagram (see ILV 845- 03-53) uniform chromaticity scale diagram produced by plotting in rectangular co-ordinates v' against u', quantities defined by the equations u' = 4X/(X + 15Y + 3Z) = 4x/(-2x + 12y + 3) v' = 9Y/(X + 15Y + 3Z) = 9y/(-2x + 12y + 3) X, Y, Z are the tristimulus values in the CIE 1931 or 1964 standard colorimetric systems, and x, y are the corresponding chromaticity coordinates of the colour stimulus considered. 3.6 colour temperature T c (see ILV 845-03-49) temperature of a Planckian radiator whose radiation has the same chromaticity as that of a given stimulus 1 This definition is a revision of the definition given in CIE 17.4-1987. ISO 10526:2007(E) CIE S 014-2/E:2006 © CIE 2006 — All rights reserved © ISO 2007 — All rights reserved 2 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=IHS Employees/1111111001, User=leee, leee Not for Resale, 11/22/2007 18:44:35 MSTNo reproduction or networking permitted without license from IHS - - ` , ` ` ` , ` ` , ` , , ` , ` , ` , , ` ` , ` ` , ` , ` , - ` - ` , , ` , , ` , ` , , ` - - - 3.7 correlated colour temperature T cp (see CIE 15:2004 Section 9.5) 2 temperature of a Planckian radiator having the chromaticity nearest the chromaticity associated with the given spectral distribution on a diagram where the (CIE 1931 standard observer based) u', 2/3v' coordinates of the Planckian locus 3 and the test stimulus are depicted NOTE 1: The concept of correlated colour temperature should not be used if the chromaticity of the test source differs more than ∆C = [(u' t -u' P ) 2 + 9 4 ⋅(v' t -v' P ) 2 ] 1/2 = 5x10 -2 from the Planckian radiator, where u' t ,v' t refer to the test source, u' P ,v' P to the Planckian radiator. NOTE 2: Correlated colour temperature can be calculated by a simple minimum search computer program that searches for that Planckian temperature that provides the smallest chromaticity difference between the test chromaticity and the Planckian locus or by any other equivalent method. 4 3.8 daylight illuminant (see ILV 845-03-11) illuminant havin