Has anyone done a study on the optimum brightness? I don't use the higher settings on any of my lights. I find that if I have my lights too bright, nearby things are well luminated. But the trade-off is I don't see small reflectors on a shoe further away. Or that person wearing black sweats and walking a black lab. My current solution is to have a light on my helmet, so I can look away from close, bright things light speed limit signs. I also have a brighter light on my handlebar.