Cloud Lighting is a name I made up because I don't know what it is called. Think I may have read it in a cannabis culture mag years ago. Some growers in Holland that would turn some of their lights off during flower to mimic the fact that sometimes clouds move in front of the sun and block light. Anyway the results were that by using half the watts they got 1.5 the yield compared to using all the lights. I thought it was very interesting but I never could utilize it.