ISO INTERNATIONAL STANDARD 5763 Second edition 1989-10-01 Photography - Electronic flash equipment - Automatic controlofexposure Photographie - Equipement électronique a éclairs - Controle automatique de Iexposition Reference number ISO 5763 :1989 (E) ISO 5763 : 1989 (E) 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. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. Draft International Standards adopted by the technical committees are circulated to the member bodies for approval before their acceptance as International Standards by the ISo Council. They are approved in accordance with ISO procedures requiring at least 75 % approval by the member bodies voting. International Standard ISO 5763 was prepared by Technical Committee ISO/TC 42, Photography. This second edition cancels and replaces the first edition (ISo 5763 : 1982), of which it constitutes a minor revision. Annex A of this International Standard is for information only. ISO 1989 Allrights reserved. 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 the publisher. International Organization for Standardization Case postale 56 . CH-1211 Geneve 20 . Switzerland Printed in Switzerland i ISO5763:1989 (E) Introduction This International Standard gives conditions and measuring values for the calibration of electronic flash equipment with automatic control of exposure. The calibration values are principally related to the exposure of film in the focal plane. They are equivalentto the exposure inthefocal plane of a camerawith anautomatic exposure control mechanism (see ISO 2721) and are related to an object exposure number(seeIsO1230). To establish this correlation it is assumed that most pictures are taken under rather similar conditions. tions of flash equipment may, however, require the consideration of calibration values other than those given in this International Standard. Certain electronic flash equipment with automatic control of exposure, designed ex- clusively for a particular camera, may not comply with some of the requirements specified in this International Standard, which are prepared for "general purpose" automatic flash equipment. This is because, in designing "special" flash equipment, all parameters of the particular camera are taken into consideration, i.e. camera lens transmittance, vignetting, the relationship between the field of taking lens and the ment, etc., and these parameters will sometimes be different from those of the "average"' camera. Tolerances may also be different for the special automatic flash equipment. For example, equipment for instant picture cameras will require a tolerance of ±1/3 Ey whereas equipment for the cameras using 110 size colour negative films according to iSO 5800, the tolerance + 3 Ev or -1 Ev is acceptable. Furthermore, even for general purpose automatic flash equipment, deviation from the "average" conditions by special scenes or by special constructions of flash equipment may require the consideration of calibration values otherthanthosegiven in thisInter national Standard. Therefore, when testing electronic flash equipment with automatic control of exposure according to the methods specified in this International Standard, the above- mentioned special cases must be taken into consideration. A photographic check of the correct exposure is recommended.