EN 12665:2024

SLOVENSKI STANDARD
01-november-2024
Svetloba in razsvetljava - Osnovni izrazi in merila za specifikacijo zahtev za
razsvetljavo
Light and lighting - Basic terms and criteria for specifying lighting requirements
Licht und Beleuchtung - Grundlegende Begriffe und Kriterien für die Festlegung von
Anforderungen an die Beleuchtung
Lumière et éclairage - Termes de base et critères pour la spécification des exigences en
éclairage
Ta slovenski standard je istoveten z: EN 12665:2024
ICS:
01.040.91 Gradbeni materiali in gradnja Construction materials and
(Slovarji) building (Vocabularies)
91.160.01 Razsvetljava na splošno Lighting in general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 12665
EUROPEAN STANDARD
NORME EUROPÉENNE
May 2024
EUROPÄISCHE NORM
ICS 01.040.91; 91.160.01 Supersedes EN 12665:2018
English Version
Light and lighting - Basic terms and criteria for specifying
lighting requirements
Lumière et éclairage - Termes de base et critères pour Licht und Beleuchtung - Grundlegende Begriffe und
la spécification des exigences en éclairage Kriterien für die Festlegung von Anforderungen an die
Beleuchtung
This European Standard was approved by CEN on 15 March 2024.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2024 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 12665:2024 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
Introduction . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
3.1 Eye and vision . 5
3.2 Light and colour . 8
3.3 Lighting equipment . 27
3.4 Daylight . 40
3.5 Lighting installations . 43
3.6 Lighting measurements . 57
4 Framework for the specification of lighting requirements . 59
4.1 General . 59
4.2 Illuminance . 59
4.3 Luminance . 59
4.4 Glare . 59
4.4.1 Disability glare . 59
4.4.2 Discomfort glare . 59
4.5 Colour . 60
4.5.1 Colour rendering . 60
4.5.2 Light source colour . 60
4.6 Energy. 60
4.7 Maintenance . 60
4.7.1 Maintenance . 60
4.7.2 Maintenance factor . 60
4.8 Measurements and calculations . 60
Annex A (informative) Additional explanation of defined terms . 61
Bibliography . 64
Index of terms . 68
European foreword
This document (EN 12665:2024) has been prepared by Technical Committee CEN/TC 169 “Light and
lighting”, the secretariat of which is held by DIN.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by November 2024, and conflicting national standards shall
be withdrawn at the latest by November 2024.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN 12665:2018.
The main technical changes in this revision of EN 12665:2018 are through harmonization with the
revised CIE International Lighting Vocabulary, CIE S 017:2020.
Any feedback and questions on this document should be directed to the users’ national standards body.
A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organisations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia,
Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland,
Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of North
Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the United
Kingdom.
Introduction
This document specifies a basic framework intended to be used for the specification of lighting
requirements.
Where a term is contained in CIE Publication CIE S 017:2020 ILV, International Lighting Vocabulary or
IEC 60050-845, International Electrotechnical Vocabulary, Part 845: Lighting, a reference is given to the
equivalent term where the terms in both documents are, for all practical purposes, identical.
NOTE Definitions from CIE S 017:2020 and IEC 60050-845:2020 contain notes providing information on the
numbering in previous versions of both documents. These notes were generally omitted as they are not necessary
for application in European standards.
For some terms, additional explanation is given in informative Annex A.
The lighting requirements for a space are determined by the need to provide:
— adequate illumination for safety and movement;
— conditions that will facilitate visual performance and colour perception;
— acceptable visual comfort for the occupants in the space.
The relative importance of these factors will vary for different applications. This basic framework covers
aspects in the field of vision, photometry and colourimetry, involving natural and man-made optical
radiation over the UV, the visible and the IR regions of the spectrum, and application subjects covering
all usages of light, indoors and outdoors, including environmental, energy and sustainability
requirements and aesthetics and non- image forming biological aspects.
Peculiar and specific terms can be defined in application standards.
Considerations should also be given to the energy used by lighting and to maintenance.
The parameters that need to be specified to ensure good visual conditions and an efficient lighting
installation are common to many applications. These are dealt with in Clause 4 of this document.
LED terms and definitions already existing within EN 62504 have not been included in this document.
For terms and definitions concerning daylight openings within a building envelope the following
standards may also be consulted:
— EN 12216, Shutters, external blinds, internal blinds — Terminology, glossary and definitions
— EN 12519, Windows and pedestrian doors — Terminology

1 Scope
This document defines basic terms and definitions for use in all lighting applications. This document also
sets out a framework for the specification of lighting requirements, giving details of aspects that are to be
considered when setting those requirements.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp/ui
— IEC Electropedia: available at https://www.electropedia.org/
3.1 Eye and vision
3.1.1
adaptation
process by which the state of the visual system is modified by previous and present exposure to stimuli
that can have various luminance values, spectral distributions and angular subtenses
Note 1 to entry: Adaptation to specific spatial frequencies, orientations, sizes, etc. is recognized as being included
in this definition.
Note 2 to entry: The terms light adaptation and dark adaptation are also used, the former when the luminances
of the stimuli are of at least several candelas per square metre, and the latter when the luminances are of less than
some hundredths of a candela per square metre.
[SOURCE: IEC 60050-845:2020 845-22-012 / CIE S 017:2020; 17-22-012, modified - Note 2 to entry
replaced]
3.1.2
accommodation
adjustment of the dioptric power of the crystalline lens by which the image of an object, at a given
distance, is focused on the retina
[SOURCE: IEC 60050-845:2020 845-22-086 / CIE S 017:2020; 17-22-086]
3.1.3
visual acuity
visual resolution
capacity for seeing distinctly fine details that have very small angular separation
[SOURCE: IEC 60050-845:2020 845-22-077 / CIE S 017:2020; 17-22-077]
3.1.4
brightness
attribute of a visual perception according to which an area appears to emit, transmit or reflect, more or
less light
Note 1 to entry: The use of this term is not restricted to primary light sources.
[SOURCE: IEC 60050-845:2020 845-22-059 / CIE S 017:2020; 17-22-059]
3.1.5
contrast
perceived contrast
assessment of the difference in appearance of two or more parts of a field seen
simultaneously or successively
EXAMPLE 1 Brightness contrast, lightness contrast, colour contrast, simultaneous contrast, successive contrast.
EXAMPLE 2 By the proportional variation in contrast near the luminance threshold (ΔL/L) or by the ratio of
luminances for much higher luminances (L /L ).
1 2
[SOURCE: IEC 60050-845:2020 845-22-089 / CIE S 017:2020; 17-22-089, modified - example 2 added]
3.1.6
brightness contrast
subjective assessment of the difference in brightness between two or more surfaces seen simultaneously
or successively
3.1.7
colour contrast
subjective assessment of the difference in colour between two or more surfaces seen simultaneously or
successively
3.1.8
glare
condition
...