INTERNATIONALISOSTANDARD9336-3First edition1994-10-15Optics and optical instruments -Opticaltransfer function一Application一Part 3:TelescopesOptique et instruments d'optique-Fonction de transfert optique-Application-Partie 3:TelescopesISOReference number1S093363:1994(E)1S09336-3:1994E)ForewordISO (the International Organization for Standardization)is a worldwidefederation of national standards bodies (ISO member bodies).The workof preparing International Standards is normally carried out through ISOtechnical committees.Each member body interested in a subject forwhich a technical committee has been established has the right to berepresented on that committee.International organizations,governmentaland non-governmental,in liaison with ISO,also take part in the work.ISOcollaborates closely with the International Electrotechnical Commission(IEC)on all matters of electrotechnical standardization.Draft International Standards adopted by the technical committees arecirculated to the member bodics for voting.Publication as an InternationalStandardirequires approval by at least 75%of the member bodies castinga voteISO/TC 1:72,Optics and optical instruments,Subcommittee SC 1,Funda-mental standards.ISO 9336 consists of the following parts,under the general title Optics andoptical instrumentsPart 1:Interchangeable lenses for 35 mm still cameras-Part 2:Lenses for office copiersPart 3:TelescopesAnnexes A and B of this part of ISO 9336 are for information only.or utilized in any form or by any means,electronic or mechanical,including photocopying andmicrofilm,without permission in writing from the publisher.International Organization for StandardizationCase Postale 56.Cll-1211 Geneve 20.SwitzerlandPrinted in SwitzcrlandINTERNATIONAL STANDARD ISOIS09336-3:1994E)Optics and optical instruments -Optical transferfunction一Application一Part 3:Telescopes1 Scope3 DefinitionsThis part of ISO 9336 spccifics a method of testingFor the purposes of this part of ISO 9336.the defi-telescopes in terms of imaging states aimed at mak-nitions given in ISO 9334 apply.ing valid optical transfer function measurements.Information is also given on the testing of some of4General description of test specimentheir components and sub-assemblies.types and the relevance of OTF testsThe specimens considered are direct view telescopeswhich generally give the observer an enlarged pres-entation of a distant scene and include many instru-2 Normative referencesments such as theodolite telescopes.hand-heldbinoculars and vehicle-mounted observation instrusThe following standards contain provisions which,mentsthrough reference in this text,constitute provisionsof this part of ISO 9336.At the time of publication,theSome,such as theodolite telescopes,have smaleditions indicated were valid.All standards are subjectfields of view,say +1 in object space,present a flatto revision,and parties to agreements based on thisfield with little or no astigmatism and have magnipart of ISO 9336 are encouraged to investigatc thefications of about x 20.On the other hand,binoculargpossibility of applying the most recent editions of theand other similar instruments have larger fields ofstandards indicated below.Mcmbers of IEC and ISOview,say up to +3,5 in object space with a magni-maintain registers of currently valid Internationalfication of x 10.Such instruments can have significantStandards.curvature of field coupled with astigmatism depend-ing on the aims of the optical designer.For example,ISO 9334:-1 Optics and optical instruments -Op-curvature of field can be minimized in one section buttical transfer function-Definitions and mathematicalconsiderable astigmatism can be left or alternativelythe astigmatism can be reduced to a negligibly lowlevel with field curvature of 1 or 2 dioptres at the edgeISO 9335:-11,Optics and optical instruments -Op-of the field.tical transfer function-Principles and procedures ofIdeally,instruments would be best with no astig-matism and no curvature of field coupled with goodCIE Publication No.18.2 (1983),The basis of physicalchromatic correction but frequently compromises asphotometry.mentioned above must be tolerated.1)To be published.1