Originally Posted by vpwphoto
LED light like Mercury Vapor and others is "spikey" in color emission spectra.
As opposed to incandescent Tungsten, Arc, Xenon, and the good old Sun more smooth.
fluorescent is somewhere in-between.
White LED's have incorporated fluorescant substances (just like fluorescant lamps). They are less spiky than low colour quality fluorescant lamps, but still have peaks.