Encyclopedia of Color Science and Technology

Living Edition
| Editors: Ronnier Luo

Spectral Power Distribution

  • Yi-Chen Chuang
Living reference work entry
DOI: https://doi.org/10.1007/978-3-642-27851-8_352-1



Spectral power distribution (SPD) is a function of wavelength and describes the amount of optical radiation across part of a spectrum. SPD usually describes optical radiation emitted by a light source, but generally, SPD can be applied to describe optical radiation reflected by an object, or transmitted from a transparent/semi-transparent object.

According to the definition of the Illuminating Engineering Society of North America (IESNA), SPD is “a pictorial representation of the radiant power emitted by a light source at each wavelength or band of wavelengths in the visible region of the electromagnetic spectrum.” Ideally, SPD should be expressed in units of W/nm. However, in some of the literature, SPD is a general term used to describe any radiometric or photometric quantity as a function of wavelength (with corresponding units). In many conventional cases, SPD is referred to as radiant power per unit area as a function of...


Light Source Optical Radiation Color Property Color Quality Solid State Lighting 
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  1. 1.
    Webster, J.G. (ed.): The Measurement, Instrumentation, and Sensors Handbook. Springer, Heidelberg (1999)Google Scholar
  2. 2.
    Peres, M.R.: The Focal Encyclopedia of Photography. Focal Press, Amsterdam (2007)Google Scholar
  3. 3.
    Fairchild, M.D.: Color Appearance Models. Wiley, Hoboken (2005)Google Scholar
  4. 4.
    Grum, F.C.: Optical Radiation Measurements, vol. 1. Academic, New York (1979)Google Scholar
  5. 5.
    CIE, Technical Report: Colorimetry, 3rd ed., Publication 15:2004, CIE Central Bureau, Vienna (2004)Google Scholar
  6. 6.
    Joint ISO/CIE Standard: ISO 10526:1999/CIE S005/E-1998 and CIE Standard Illuminants for ColorimetryGoogle Scholar
  7. 7.
    McCluney, W.R.: Introduction to Radiometry and Photometry. Artech House, Boston (1994)Google Scholar
  8. 8.

Copyright information

© Springer Science+Business Media New York 2015

Authors and Affiliations

  1. 1.Center for Measurement StandardsIndustrial Technology Research InstituteHsinchuTaiwan