> The diode itself produces only a peak in the spectrum. Phosphors are used to convert the light to a wide spectrum. There are different kinds of phosphors, and there can be multiple coatings of different types. So you can also have different qualities -- and the quality can be very good.
Thanks for the explanation. I've been learning a little about light sources; based on my limited knowledge, I wouldn't expect that the full spectrum (or spectral power distribution (SPD)) of daylight could be replicated by hacking together LEDs and phosphors, though perhaps the untrained eye would not be cognizant of the difference. Can they really pull off 'daylight'?