The question of white illumination

What is the colour of white light? This may seem like an odd question. After all, white light is white -- the combination of all the colours of the rainbow. And yet, depending on the context, white light does not always appear to our eye as white. When an observer stands in an atrium filled with "white" daylight and looks at a gallery illuminated with "white" tungsten-halogen lamps, the artificial light appears yellow or unnaturally warm. When the visitor stands in an artificially lighted space where there is no reference to daylight, the light appears "white" and a small spot of natural light will appear blue or unnaturally cool compared to the primary tungsten-halogen light source. So, which light is "white"? The answer is: both. (In fact, there is a wide variety of "whites," ranging from cool to warm, determined by the varying proportion of blue to red).

Further pounding on the intricacies of optical phenomenon in vlogposting , Sam Renseiw captured a short sequence of white retinal light, complete with warm-up choir. An almost snow-blinding video, contextualized in an architectural peak, with both natural and incandescent light- on a late afternoon in Bagsværd (55°45'42.67''N 12°26'38.39''E). View it by clicking here, or enter the composition above. (patafilm #171, 01'22'', 2.4 MB, mov/quicktime- Flash version at Blip.tv)