ISO INTERNATIONAL STANDARD 14490-2 First edition 2005-11-01 Optics andoptical instruments-Test methods for telescopic systems - Part 2: Test methods for binocular systems Optique et instrumentsd'optique-Methodes d'essaipoursystemes telescopiques Partie2:Methodesd'essaipoursystemesbinoculaires Reference number ISO 14490-2:2005(E) ii Foreword IsO (the International Organization for Standardization) is a worldwide federation of national standards bodies non-governmental, in liaison with isO, also take part in the work. iso collaborates closely with the InternationalElectrotechnicalCommission(lEC)onallmattersofelectrotechnicalstandardization. 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 75% of the memberbodies casting a vote. ISO 14490-2 was prepared by Technical Committee ISO/TC 172, Optics and photonics, Subcommittee SC 4 Telescopic systems. Iso 14490 consists of the following parts, under the general title Optics and optical instruments- Test methodsfortelescopicsystems: Part 1:Test methods for basic characteristics Part 2: Test methods for binocular systems Part 3: Test methods fortelescopic sights Part 4: Test methods for astronomical telescopes Part5:Test methods for transmittance Part 6: Test methods for veiling glare index Part7:Testmethodsforlimitofresolution The following part is under preparation: Part 8: Test methods for night-vision devices ii blank OpticsandopticalinstrumentsTest methodsfortelescopic systems - Part 2: Test methods for binocular systems Scope This part of Iso 14490 is applicable to binocular telescopic systems and specifies the test methods for determination of the following characteristics: non-parallelism of the axes of bundles of rays emergent from the eyepieces; interpupillary distance; relative difference in magnification; focusing difference between telescopes of binocular systems. 2Normative references document (including any amendments) applies. Iso14132-1:2002,Opticsandopticalinstruments-Vocabularyfortelescopicsystems—Part1:General termsandalphabeticalindexesoftermsin/sO14132 ISO14132-2:2002,Opticsandopticalinstruments-Vocabularyfortelescopicsystems-Part2:Termsfor binoculars, monoculars and spotting scopes IsO14490-1:2005,Opticsandopticalinstruments-Testmethodsfortelescopicsystems—Part1:Test methodsforbasiccharacteristics 3Terms and definitions For the purposes of this document, the terms and definitions given in IsO 14132-1 and isO 14132-2 apply Measurement of non-parallelism of axes 4.1 General The optical axes of both telescopes of the instrument shall be parallel so as to ensure normal binocular vision telescopes is based on the physiological properties of the human eye. 1 The measurement of the non-parallelism of axes shall be carried out at the following interpupillary distances: 60 mm, 65 mm, 70 mm. 4.2Testequipment 4.2.1 The measurements should be made by means of the test arrangement shown in Figure 1. 4.2.2 The visual axes of the collimators and measuring telescopes shall be parallel. The deviation from parallelism should not exceed 20" of arc. It is permissible to use a single collimator if the diameter of the collimator lens is at least 160 mm. 345 6 8 Key light source condenser filter (approx. 0,55 μm) 3 diffusing plate reticle 5 6 collimator lens test specimen with deviation “divergence" 8 measuringtelescope scale 9 Figure1Testarrangementfor measuring non-parallelismof axes ofbundlesemergentfromthe eyepieces in binocular instruments 4.2.3The test targets in the form of cross-lines shall be placed in the focal planes of the collimator objectives. and measuring scales. 2 4.3 Preparation and carrying out of measurements 4.3.1 The eyepieces of each measuring telescope shall be adjusted to obtain the sharp image of its own reticle. 4.3.2 When the test specimen is removed,