ISO 14135-2:2021

Optics and photonics - Specifications for telescopic sights - Part 2: High-performance instruments

This document applies to high-performance telescopic sights, used on hand-held firearms and airguns. It contains a classification of the usage of telescopic sights and specifies interfaces, minimum requirements and tolerances to their performances. General-purpose telescopic sights are specified in ISO 14135-1.

Optique et photonique — Spécifications pour lunettes de pointage — Partie 2: Instruments haute performance

General Information

• Status: Published
• Publication Date: 10-Feb-2021
• ICS: 37.020 - Optical equipment
• Technical Committee: ISO/TC 172/SC 4 - Telescopic systems
• Drafting Committee: ISO/TC 172/SC 4/WG 2 - Telescopic devices
• Current Stage: 9092 - International Standard to be revised
• Start Date: 14-Apr-2025
• Completion Date: 13-Dec-2025

Relations

• Revises: ISO 14135-2:2017 - Optics and photonics - Specifications for telescopic sights - Part 2: High-performance instruments
• Effective Date: 23-Apr-2020

Overview

ISO 14135-2:2021 - Optics and photonics - Specifications for telescopic sights - Part 2: High-performance instruments defines minimum performance requirements, interfaces and tolerances for high‑performance telescopic sights used on hand‑held firearms and airguns. The standard covers classification by end use (airguns, pistols/handgun scopes, rifles), mechanical interfaces, fundamental optical and mechanical requirements, consumer information (marking and brochures), and conformity claims.

Key topics and technical requirements

• Classification: scopes are classified by intended use - airgun, pistol (handgun) or rifle - because performance expectations differ by application.
• Interfaces and dimensions: interface areas are cylindrical (central tube and objective tube) or may use a dovetail. Recommended central tube diameters include 19 mm or 22 mm (airguns); 25.4 mm (1 in) or 30 mm (handguns); and common rifle sizes such as 25.4 mm, 26 mm, 30 mm, 34 mm, 36 mm (see Annex A).
• Optical minimums: the standard specifies minimum values and formulas for key optical metrics:
  • Eye relief: example minimums - airguns 50 mm, pistols 250 mm, rifles 70 mm.
  • Resolution: given as functions of D (entrance pupil diameter) and Γ (magnification), e.g. for exit pupil ≤ 4.5 mm resolution ≤ 300 / D (arc seconds).
  • Dioptre adjustment range: at least 3 dioptres (independent for elevation and windage for pistols/rifles).
  • Total reticle adjustment range: 30 arc minutes for rifles/pistols.
  • Coatings: each glass‑to‑air surface shall be antireflection‑coated.
• Tolerances and testing: magnification, field of view, entrance pupil, parallax, reticle centering, reticle tilt/tracking and line‑of‑sight shift tolerances are specified. Conformity testing uses referenced methods in ISO 14490 series (test methods for telescopic systems) and environmental tests in ISO 20711.
• Consumer information & marking: required markings include magnification, entrance pupil diameter, manufacturer, product ID, serial number and zero dioptre position. Product brochures must list technical data (e.g. field of view, exit pupil, resolution/MTF, light transmission, eye relief and critical eye relief, parallax‑free distance, reticle click value, mechanical dimensions, mass, temperature and water‑tightness).

Applications and users

ISO 14135-2 is intended for:

• Manufacturers and designers of high‑performance telescopic sights to define product specifications and test acceptance criteria.
• Test laboratories and quality assurance teams performing optical/mechanical conformity testing.
• Procurement and regulatory teams specifying performance for law enforcement, competitive shooting, hunting and specialized airgun or handgun optics.
• Distributors and technical writers preparing compliant product datasheets and manuals.

Related standards

• ISO 14135-1 (general‑purpose telescopic sights)
• ISO 14132 series (vocabulary for telescopic systems)
• ISO 14490 series (test methods for telescopic systems)
• ISO 20711 (environmental test requirements)

Keywords: ISO 14135-2, telescopic sights, high-performance optics, eye relief, entrance pupil, reticle, optical tolerances, scope interface dimensions.

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 14135-2
Fourth edition
2021-02
Optics and photonics — Specifications
for telescopic sights —
Part 2:
High-performance instruments
Optique et photonique — Spécifications pour lunettes de pointage —
Partie 2: Instruments haute performance
Reference number
©
ISO 2021
© ISO 2021
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii © ISO 2021 – All rights reserved

Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Classification . 2
5 Interfaces . 2
6 Fundamental requirements . 2
7 Consumer information . 4
7.1 Marking . 4
7.2 Information brochures . 4
7.3 Conformity . 4
Annex A (informative) Recommended interface dimensions . 6
Bibliography . 9
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.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
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. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www .iso .org/
iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 172, Optics and photonics, Subcommittee
SC 4, Telescopic systems.
This fourth edition cancels and replaces the third edition (ISO 14135-2:2017), which has been
technically revised. The main changes compared to the previous edition are as follows:
— critical eye relief added to the product information.
A list of all parts in the ISO 14135 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
iv © ISO 2021 – All rights reserved

INTERNATIONAL STANDARD ISO 14135-2:2021(E)
Optics and photonics — Specifications for telescopic
sights —
Part 2:
High-performance instruments
1 Scope
This document applies to high-performance telescopic sights, used on hand-held firearms and
airguns. It contains a classification of the usage of telescopic sights and specifies interfaces, minimum
requirements and tolerances to their performances.
General-purpose telescopic sights are specified in ISO 14135-1.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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, Optics and photonics — Vocabulary for telescopic systems — Part 1: General terms and
alphabetical indexes of terms in ISO 14132
ISO 14132-3, Optics and photonics — Vocabulary for telescopic systems — Part 3: Terms for telescopic sights
ISO 14490-1, Optics and optical instruments — Test methods for telescopic systems — Part 1: Test methods
for basic characteristics
ISO 14490-3, Optics and photonics — Test methods for telescopic systems — Part 3: Test methods for
telescopic sights
ISO 14490-5, Optics and photonics — Test methods for telescopic systems — Part 5: Test methods for
transmittance
ISO 14490-7, Optics and photonics — Test methods for telescopic systems — Part 7: Test methods for limit
of resolution
ISO 20711, Optics and photonics — Environmental requirements — Test requirements for telescopic systems
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 14132-1 and ISO 14132-3 apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsin
...