ISO 14490-2:2005

INTERNATIONAL ISO
STANDARD 14490-2
First edition
2005-11-01
Optics and optical instruments — Test
methods for telescopic systems —
Part 2:
Test methods for binocular systems
Optique et instruments d'optique — Méthodes d'essai pour systèmes
télescopiques —
Partie 2: Méthodes d'essai pour systèmes binoculaires

Reference number
©
ISO 2005
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.

©  ISO 2005
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 2005 – All rights reserved

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, 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.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
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 member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
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
methods for telescopic systems:
⎯ Part 1: Test methods for basic characteristics
⎯ Part 2: Test methods for binocular systems
⎯ Part 3: Test methods for telescopic sights
⎯ Part 4: Test methods for astronomical telescopes
⎯ Part 5: Test methods for transmittance
⎯ Part 6: Test methods for veiling glare index
⎯ Part 7: Test methods for limit of resolution
The following part is under preparation:
⎯ Part 8: Test methods for night-vision devices

INTERNATIONAL STANDARD ISO 14490-2:2005(E)

Optics and optical instruments — Test methods for telescopic
systems —
Part 2:
Test methods for binocular systems
1 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.
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.
ISO 14132-1:2002, Optics and optical instruments — Vocabulary for telescopic systems — Part 1: General
terms and alphabetical indexes of terms in ISO 14132
ISO 14132-2:2002, Optics and optical instruments — Vocabulary for telescopic systems — Part 2: Terms for
binoculars, monoculars and spotting scopes
ISO 14490-1:2005, Optics and optical instruments — Test methods for telescopic systems — Part 1: Test
methods for basic characteristics
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 14132-1 and ISO 14132-2 apply.
4 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
during observation through the instrument. The acceptable degree of non-parallelism of optical axes of the
telescopes is based on the physiological properties of the human eye.
The measurement of the non-parallelism of axes shall be carried out at the following interpupillary distances:
⎯ 60 mm,
⎯ 65 mm,
⎯ 70 mm.
4.2 Test equipment
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.

Key
1 light source
2 condenser
3 filter (approx. 0,55 µm)
4 diffusing plate
5 reticle
6 collimator lens
7 test specimen with deviation “divergence”
8 measuring telescope
9 scale
Figure 1 — Test arrangement for measuring non-parallelism of axes of bundles emergent from the
eyepieces in binocular instruments
4.2.3 The test targets in the form of cross-lines shall b
...