ISO/DIS 21094

ISO/TC 172/SC 4

Secretariat: DIN

Date: 2025-12-19

Optics and photonics — Telescopic systems — Specifications for analog night vision devices

DIS stage

© ISO 2025

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Contents

Foreword

Scope

Normative references

Terms and definitions

Specifications

General

Tolerances

Minimum requirements for optical charateristics

Consumer information

Designation and marking

Information provided by the manufacturer

Bibliography

Foreword

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This document was prepared by Technical Committee ISO/TC 172, Optics and photonics, Subcommittee SC 4, Telescopic systems.

This second edition cancels and replaces the first edition (ISO 21094:2008), which has been technically revised.

The main changes compared to the previous edition are as follows:

• eight new terms have been defined;
• Figure 1 was introduced to illustrate the meaning of monoculars, binoculars and bioculars.
• Reference to ISO 20711 was introduced in 4.1;
• Tolerances and minimum requirements for optical characteristics have been defined for general purpose instruments and for high performance instruments, instead of binoculars and monoculars and goggles;
• limit of resolution is defined in relation to the resolution of the image intensifier.

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.

Optics and photonics — Telescopic systems — Specifications for analog night vision devices

This document applies to analog night vision devices such as monoculars, binoculars and bioculars that are used under extreme low light conditions, at night or in dark rooms, for observation activities, search and rescue actions, performing urgent repairs in the dark, night‑time surveillance and security, night hunting and fishing (where legal), night driving and exploring dark spaces like caves or tunnels.

This document does not cover analog night and thermal imaging vision telescopic sights and front attachments.

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 14490-8, Optics and optical instruments — Test methods for telescopic systems — Part 8: Test methods for night-vision devices

ISO 20711, Optics and photonics — Environmental requirements — Test requirements for telescopic systems

For the purposes of this document, the terms and definitions given in ISO 14132-1, ISO 14132-2, ISO 14132-5 and the following apply.

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp

analog night vision monocular

night vision device that allows the user to use only one eye for viewing, which includes an objective lens, an image intensifier and an eyepiece

Note 1 to entry: A night vision monocular is a system with a single optical axis (see Figure 1).

analog night vision binoculars

night vision device that allows the user to use both eyes for viewing, with an independent channel for each eye including its own objective lens, image intensifier and eyepiece.

Note 1 to entry: Night vision binoculars are designed as two interlinked night vision monoculars having parallel optical axes (see Figure 1).

analog night vision biocular

night vision device, which includes a single objective lens, an image intensifier and an eyepiece, with a sufficiently large aperture to enable both eyes to observe an image simultaneously

Note 1 to entry: A night vision biocular is a system with a single optical axis (see Figure 1). Compared to a binocular system, the biocular system is free from parallelism error between axes.

analog night vision split biocular

night vision device, which includes a single objective lens, a single image intensifier, two eyepieces and a split system, the same image being presented to both eyes

Figure 1 - Illustration of monocular, binocular and biocular systems

Key

1 objective lens

2 image intensifier

3 eyepiece

4 eye

5 split system

A Monocular system

B Binocular system

C Biocular system

D Split biocular system

Figure 1 — Illustration of monocular, binocular and biocular systems

Note 1 to entry: See Figure 1.

analog night vision goggles

head mounted (e.g. on helmet or harness) night vision device (monocular, binoculars or biocular type) for hands-free operation

eye relief

distance measured along the optical axis from the vertex of the last optical surface of the eyepiece to the plane in which the eye’s pupil is placed, over which the full field of view can be overlooked without noticeable vignetting and in relation to which aberration correction is performed

Note 1 to entry: Many image intensifiers have a spherical screen. In this case it is important to place the eye at the nominal value of the eye relief because the aberration correction is very sensitive in relation to this distance.

eye relief range

distance range measured along the optical axis, from the vertex of the last optical surface to the eye’s pupil, over which the full field of view can be overlooked without noticeable vignetting

Note 1 to entry: The eye relief range can be particularly important for night vision binoculars and split bioculars to compensate the differences of the interpupillary distance from the nominal value for which the optical system was calculated, if the interpupillary distance is not adjustable or when the range of adjustment is not big enough.

Fundamental requirements are defined by minimum values or tolerances for important characteristics of analog night vision monoculars, binoculars and bioculars.

Tolerances specify maximum deviations between measured and nominal values. Nominal values shall be laid down by the manufacturing or trading company.

Monoculars, binoculars and bioculars shall comply with the environmental requirements relative to the respective instrument type, as appropriate. These environmental requirements are specified in ISO 20711.

The tests for compliance of analog night vision devices to values and tolerances specified in Table 1 and Table 2 shall be carried out in accordance with ISO ISO 14490-8.

Tolerances and minimum requirements for optical characteristics are defined for general purpose instruments and for high performance instruments.

Wherever normalized conditions are mentioned in definitions of this document, reference should be made to standards and other documents that describe specific test methods.

Acceptable deviations of the optical characteristics of analog night vision monoculars, binoculars and bioculars shall be within the limits given in Table 1.

Table 1 — Acceptable deviations of optical characteristics

Values of optical characteristics for analog night vision monoculars, binoculars and bioculars shall be not less of those given in Table 2.

Table 2 — Minimum requirements for optical characteristics

For identification and operation, analog night vision monoculars, binoculars and binoculars shall have the designation and markings as specified in Table 3.

Table 3 — Designation and marking

Product catalogues, user manuals and other technical information brochures for analog night vision monoculars, binoculars and binoculars shall provide complete information at least on technical characteristics enlisted in Table 4.

Table 4 — Information provided by the manufacturer

Bibliography

[1] ISO 14132-1, Optics and photonics — Vocabulary for telescopic systems — Part 1: General terms and alphabetical indexes of terms in ISO 14132

[2] ISO 14132-2, Optics and photonics — Vocabulary for telescopic systems — Part 2: Terms for binoculars, monoculars and spotting scopes

[3] ISO 14132-5, Optics and photonics — Vocabulary for telescopic systems — Part 5: Terms for night vision devices