3028 OSI) International Standard INTERNATIONAL ORGANIZATION FOR STANDARDIZATION·MEKAYHAPOAHAA OPTAHM3AUMA NO CTAHAAPTM3AUMMORGANISATION INTERNATIONALE DE NORMALISATION Photography - Camera flash illuminants Determination of ISO spectral distribution index (ISO/SDl) Photographie - lluminant type 《lampe éclair> pour photographie -- Determination de I'indice de distribution spectrale Second edition - 1984-10-15 UDC 771.448 Ref. No. 1SO 3028-1984 (E) D 3028-1984 (E) Descriptors : photography, photographic equipment, light sources, flash lamps, electronic flash tubes, illuminants, tests, optical tests, spectrum analysis, spectral distribution. Copyright International Organizationfor Standardization Price based on 7 pages efrom IHS Not for Resale Foreword 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, govern- mental and non-governmental, in liaison with ISO, also take part in the work. Draft International Standards adopted by the technical committees are circulated to the member bodies for approval before their acceptance as International Standards by least 75 % approval by the member bodies voting. international Standard ISO 3028 was prepared by Technical Committee ISO/TC 42, Photography. IS0 3028 was first published in 1974. This second edition cancels and replaces the first edition, of which it constitutes a fundamental revision. International Organization for Standardization, 1984 ? Printed in Switzerland d without license from IHS Not for Resale ISO 3028-1984 (E) INTERNATIONALSTANDARD Photography - Camera flash illuminants Determination of ISO spectral distribution index (ISO/SDl) Introduction 3 Definitions 0 This International Standard specifies a method for evaluating For the purpose of this International Standard, the terms listed the colour quality of flash lluminants used in photography. This in ISo 5/1 and the following apply: revision of Is0 3028 was considered necessary in order to recognize the spectral sensitivity of colour films as they are 3.1 source: A physical emitter of energy. presently manufactured. It also utilizes the recently approved spectral transmittance values of the IsO standard camera lens (see ISO 6728). For these reasons, spectral distribution indexes illuminant: Light having a specific spectral power 3.2 (SDl) determined according to this edition of ISO 3028 shall not distribution not necessarily provided directly by a source and be compared with those of the previous edition. not necessarily realizable by a source. Camera flash units are generally used indoors for exposing film which has been specifically designed to provide optimum 3.3 relative spectral power distribution: A description of results outdoors in daylight. Therefore, flash units should give the spectral character of radiation by the relative distribution of results with an overall colour balance equivalent to that obtain- some radiometric quantity (radiant flux, radiant intensity). ed in daylight (see ISO 7589). The ISO/SDI of a flash source, determined according to this International Standard, is a 3.4 photographic response R: The effective response of a numerical expression of the colour balance shift expected in sensitized photographic material to radiant flux. flash pictures compared with those taken in natural daylight. It is expected that this International Standard will be used by This can be represented by the equation manufacturers in the design and control of photographic light illuminants. This International Standard is intended primarily to evaluate p()2 ()s ... (1) electronic flash units and expendable sources such as flash bulbs. However, it may also be used to e