Move around
Back to Learn

Knowledge of Light

To fully utilize the power of light, a thorough understanding of lighting principals is necessary. It takes years of experience and research to accumulate the knowledge necessary to develop some of the most innovative technologies and lighting solutions in the industry.


Zumtobel is committed to furthering our understanding of lighting, which is reflected in our extensive research. We also believe that knowledge should be shared, and by doing so we hope to contribute to the advancement of the lighting industry as a whole.



These are basic lighting parameters which help us to measure, quantify and understand light. Learn more about how to measure light.

Luminous flux

  • the quantity of light emitted by a light source
  • measured in lumens (lm)


Luminous intensity

  • the quantity of light radiated in a particular direction
  • measured in candelas (cd)



  • the quantity of luminous flux falling on a surface
  • measured in lux (lx)



  • specifies the brightness of a surface
  • measured in cd/m2




As technologies advance, the definition of quality lighting has evolved. A comparison of traditional and modern quality criteria are listed below.


Traditional quality criteria

  • Glare limitation
  • Good modeling
  • Correct light color
  • Avoidance of reflections
  • Harmonious brightness distribution
  • Sufficient illumination level
  • Appropriate color rendering


New quality criteria

  • Changing lighting situations
  • Personal control
  • Energy efficiency
  • Daylight integration
  • Light as an interior design element


We can quantify these quality criteria by using a number of different measures, such as color temperature, color rendering and binning. Learn more about quality and color of light.

zumtobel learn

Thanks! You’ve been subscribed
to our mailing list.

Want to stay up to date?
Subscribe to our Newsletter.