This question has been answered by Jim Ashley-Down, managing director of Waldmann Lighting.
When trying to mimic the effects of natural light, the lighting system should follow similar patterns to the light found in nature. As with outdoors, the main illumination should originate from a large area (think sky). Ideally the light should arrive at the eyes at between 0 and 45 degrees from the horizontal, as this is close to our experience outdoors and serves to stimulate the ganglion cells inside the eye without creating glare. (The ganglion cells are the parts of the eyes most susceptible to the biological effects of daylight.)
The gradual change from colder white in the morning to warmer white in the evening should be done according to the daylight conditions found at that particular latitude. It is not as simple as starting the day with cold white light and finishing with warm, as its effectiveness depends very much on the actual time of day and what the users of the lighting are used to. Different parts of the world have different variations of daylight, so the regional location of the lighting is also an important consideration.
For the most effective results, biodynamic lighting should be all of the lighting within sight of an occupant of a space, not just the light immediately around them.
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