A brief yet explanatory video by the Premiumlight EU project. You will see the characteristics of different types of existing lamps.
You may recall that, from the standpoint of artificial light at night effects:
– light sources which are too intense and poorly oriented may cause glare
– lights with a high correlated colour temperature (a threshold has not been defined, but many researcher concur with 3500-4000K) have higher emissions in the blue part of the spectrum and, hence, stronger effects on health (Melatonin suppression, shifting of sleeping time, and other effects currently under investigation).
Kudos to Laurent Canale for pointing out the video