Flicker
Flicker from light sources is the impression of unsteadiness of visual sensation caused by rapid and repeated changes in the luminous intensity of a source.
Lighting flicker is often not noticed by non-lighting experts because it is not always visible to the naked eye. Only flicker below 100 Hz is visible flicker and can be checked with cameras or by quickly waving the hand below the light source. When using a camera, flicker is revealed in the form of disturbing lines on the screen while with the hand tests, multiple fingers are shown.Such phenomena is caused by the stroboscopic effect of flickering lighting. It is mostly related to the use of LED luminaires powered by poor quality drivers.
Research shows that flicker causes eye strain, tiredness, loss of concentration, headaches, and other health problems. Therefore special attention must be given to good and flicker-free lighting in office spaces or spaces where concentrated work takes place.
Tip from a lighting designer
At Studio De Schutter we consult our clients on the effects of lighting and flicker. The headquarters of Covivio in Berlin is one of these examples. Here, the meeting spaces which are equipped with large screens have flicker-free lighting to allow for HD video conferences.