I could be very wrong about this but I use a small RED lense light walking in. If it is a headlamp style DON'T wear it on your head, carry it in your hand ALWAYS facing down. When I think I'm 150-200yds out I'll then cup my hand around the head of the light to just let the least amount of light out to see where I'm stepping, then just close your hand up completely if you can see and normally only need it every other step or so. When I first started turkey hunting and had no idea, I would use a clear lense headlamp. Walked right by birds roosted that would never make a sound, daylight would come and they would fly down and go the other way. Switched to the red lense holding it low and straight down, Seems to have made a huge difference, can't remember the last time I spooked a bird walking in.