I use a red lens light unless something goes wrong and a need more light. foolish to not have a light on in the dark for safety's sake, but you will be able to be a whole bunch quieter if you try to be. getting set up without being detected, whether in the dark or in broad daylight, is one of the most important factors to seeing deer consistently, imo. lights don't bother deer at all. I've shined them from a stand just to see how they react. I've walked right up to pigs in the dark and shot them from 10 feet away with a light right on them. (yes, this is perfectly legal{and a little dangerous} down south where pigs are vermin)