Standardlicht

Standardlicht, in color science and lighting terminology, refers to a defined reference light source or light condition used for calibration, comparison, and reproducible measurements. The concept provides a stable, well-characterized spectral power distribution that allows observers and instruments to interpret color consistently across devices and environments.

Historically, standardlicht has its roots in international standardization efforts led by organizations such as the CIE (Commission Internationale de l'Éclairage) and national standard bodies. The aim is to enable reliable color matching, color rendering assessment, and device calibration by fixing the spectral characteristics and correlated color temperature of the light used in measurements and comparisons.

Common examples of standardlicht in practice include several standardized illuminants. A is the tungsten or incandescent standard with a spectral profile corresponding to a color temperature of about 2856 K. D65 is a daylight-type standard with approximately 6500 K, widely used in digital imaging, photography, and display calibration. D50 (about 5000 K) and D75 (about 7500 K) are other daylight-adapted standards popular in graphic arts and printing. E, the equal-energy illuminant, presents a uniform spectral distribution across wavelengths and serves as a reference in spectroscopic and theoretical contexts. Each standard illuminant has a defined spectral power distribution and is chosen for its relevance to specific industries and measurement goals.

Applications of standardlicht include colorimetry, color quality control in printing and textiles, display and camera calibration, and objective color assessments where reproducibility is essential. See also colorimetry, illuminants, and color rendering.