SIST EN ISO/CIE 11664-2:2022 PDF

Overview

EN ISO/CIE 11664-2:2022 (Colorimetry - Part 2: CIE standard illuminants) is the CEN-adopted international standard that defines three CIE standard illuminants used in colorimetry: A, D65, and D50. The document provides the relative spectral power distributions (SPDs) of these illuminants (given at 1 nm intervals from 300 nm to 830 nm) and guidance on their intended use. This edition supersedes the 2011 version and adds D50 as a CIE standard illuminant because of its wide use in graphic arts and photography.

Key topics and requirements

• Defined illuminants
  • CIE standard illuminant A - represents typical tungsten‑filament (incandescent) lighting; SPD equals a Planckian radiator at ≈ 2855.5 K.
  • CIE standard illuminant D65 - represents average daylight with a correlated colour temperature (CCT) of ≈ 6500 K.
  • CIE standard illuminant D50 - represents daylight with a CCT of ≈ 5000 K.
• Spectral data: Relative SPDs for A, D65 and D50 are included; values are provided at 1‑nm intervals from 300–830 nm (Annex A and Annex B).
• Definitions and terminology: Clarifies the difference between a defined illuminant (SPD) and a source (physical emitter), and includes terms from CIE S 017.
• Sources and realizations: CIE standard source A (practical lamp realization) is described; currently there are no CIE‑recommended physical sources for D65 and D50 in this document.
• Normative status: The SPD tables and definitions are normative; the standard is intended to harmonize colorimetric practice across laboratories and industries.

Applications and users

This standard is essential for anyone performing color measurement, color management, or lighting specification where consistent illumination definitions are required. Typical users include:

• Color scientists and metrology laboratories (computing tristimulus values and colorimetric conversions)
• Lighting engineers and luminaire manufacturers
• Print, photography, graphic arts and display industries (use of D50/D65 for viewing and proofing)
• Paints, coatings and textiles testing laboratories (CEN/TC 139 applications)
• Standards bodies and product specification teams seeking harmonized illumination references

Use of these standard illuminants improves reproducibility and comparability of color data across studies, products and international markets.

Related standards

• CIE S 017 (International Lighting Vocabulary) - terminology referenced in this document
• CIE 015 - practical data and guidelines for other CIE illuminants and spectral sampling
• Other parts of the ISO/CIE 11664 series covering colorimetry fundamentals and observer functions

Keywords: colorimetry, CIE standard illuminants, EN ISO/CIE 11664-2:2022, D65, D50, illuminant A, spectral power distribution, correlated colour temperature, color measurement, tristimulus values.