LUX REVIEW recently published an article in which Dr. Christopher Cuttle argues for an end to the lumen to make room for a better metric.
LUX writes:
His contention is that the lumen is purely a measure of visible light, and doesn’t take into account its non-visual impact on humans, such as its role in setting our sleep-wake cycle.
‘The reliance on the lumen is currently coming under pressure as practitioners seek to incorporate non-visual human responses, notably circadian effects, into their lighting solutions’.
He says that there is ‘far more to human visual sensitivity’ than is indicated by the lumen, and ‘more again when the full scope of lighting practice is taken into consideration’.
‘Lighting practitioners have been content to adopt the lumen, which is derived from the candela, for specifying quantities of light although they recognise it is inappropriate for non-visual applications such as providing for therapeutic, photosynthetic or germicidal effects, or for assessing potential for photochemical damage’, Cuttle wrote in the learned journal Lighting Research & Technology.
Check it out here.
