The long answer:
There appears to be a growing majority of keepers, as well as researchers, who suggest that misting should not be done when the lights are on. The reason given is that the natural cycle of hydration/humidity for most species is dryer daytime % (30-50%), higher nightime % (approaching 100%). When a chameleon first wakes up, the leaves are often covered in early morning condensation, and s/he can drink if spending the night in 100% humidity wasn’t quite enough water. Replicating this in captivity typically involves a mist just before lights on, so the Cham can wake up to leaves covered in water; and maybe a good mist or two after lights off. At night, some people employ a fogger for several hours as well. If additional water is required during the day, a dripper is often employed. In cases where replicating a rainy season is desirable, lights turn off for an hour in the after noon. After 15 - 30 minutes of no light, the mister goes off for a quick burst, and the lights turn back on 15-30 minutes later. This is intended to mimic clouds rolling in and dumping a quick rain. (It typically isn’t raining when the sun is out) The whole picture here is intended to mimic the conditions a chameleon would experience in the wild.
