ISO 14135-1:2021

Optics and photonics - Specifications for telescopic sights - Part 1: General-purpose instruments

This document applies to general-purpose telescopic sights, used on hand-held firearms and airguns. It contains a classification to the usage of telescopic sights and specifies interfaces, minimum requirements and tolerances to their performances. High-performance telescopic sights are specified in ISO 14135-2.

Optique et photonique — Spécifications pour lunettes de pointage — Partie 1: Instruments pour usage général

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 14135-1:2017 - Optics and photonics - Specifications for telescopic sights - Part 1: General-purpose instruments
• Effective Date: 23-Apr-2020

Overview

ISO 14135-1:2021 - "Optics and photonics - Specifications for telescopic sights - Part 1: General-purpose instruments" is the international standard for general-purpose telescopic sights used on hand‑held firearms and airguns. This fourth edition (2021) defines a classification by end use (airguns, pistols, rifles), specifies mechanical interfaces, minimum performance requirements, tolerances, marking and product information, and references environmental and test methods for conformity. High‑performance scopes are covered separately in ISO 14135-2.

Key topics and technical requirements

• Scope & classification: Applies to general‑purpose telescopic sights for airguns, pistol (handgun) and rifle use.
• Interfaces & mounting: Defines interface areas (central tube and objective tube), cylindrical shapes or central‑tube dovetails. Annex A gives recommended interface diameters (examples: 19 mm, 22 mm, 25.4 mm/1 in, 30 mm, 34 mm, 36 mm) with tolerances (typically ±0.1 mm) and sample dovetail/rail geometries.
• Fundamental performance requirements: Specifies minimum values and tolerances for important characteristics such as eye relief (examples: airguns 50 mm, pistols 250 mm, rifles 70 mm), dioptre adjustment range (3 D for pistol/rifle), total reticle adjustment (30 arc minutes for rifles/pistols), and that all glass‑to‑air surfaces shall be antireflection‑coated. Resolution, parallax and reticle tracking tolerances are defined and tested per ISO 14490 series.
• Environmental and test methods: Conformity requires environmental testing per ISO 20711 and optical/mechanical tests per ISO 14490‑1/3/5/7 (resolution, transmittance, basic characteristics).
• Consumer information & marking: Mandates on‑product marking (e.g., magnification × entrance pupil, manufacturer, serial number, dioptre zero, click value and direction) and detailed product brochures (field of view, exit pupil, MTF/resolution, light transmission, eye relief including critical eye relief, parallax‑free distance, dimensions, mass, temperature ranges, water tightness).

Practical applications / Who uses this standard

• Manufacturers & OEMs: design, tolerance control, and declaring conformity for consumer scopes.
• Test laboratories: performing optical, mechanical and environmental tests to verify compliance.
• Mount and accessory designers: ensure mechanical compatibility with standardized tube diameters and dovetail/rail forms.
• Importers, retailers & procurement teams: assess product specifications, labeling and claims.
• Regulators & certification bodies: verify safe, consistent product information and performance for user safety.

Related standards

• ISO 14135-2 (High‑performance instruments)
• ISO 14132-1 / ISO 14132-3 (Vocabulary for telescopic systems)
• ISO 14490 series (Test methods for telescopic systems)
• ISO 20711 (Environmental test requirements)

Keywords: ISO 14135-1, telescopic sights, optics and photonics, general‑purpose scope, rifle scope standards, scope mounting interface, eye relief, reticle adjustment, test methods, ISO standard.

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 14135-1
Fourth edition
2021-02
Optics and photonics — Specifications
for telescopic sights —
Part 1:
General-purpose instruments
Optique et photonique — Spécifications pour lunettes de pointage —
Partie 1: Instruments pour usage général
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 14135-1:2017), 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 14135-1:2021(E)
Optics and photonics — Specifications for telescopic
sights —
Part 1:
General-purpose instruments
1 Scope
This document applies to general-purpose telescopic sights, used on hand-held firearms and airguns.
It contains a classification to the usage of telescopic sights and specifies interfaces, minimum
requirements and tolerances to their performances.
High-performance telescopic sights are specified in ISO 14135-2.
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 bro
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