Here is a sample of 4000 OTF from two flashlight each is running 3 Cree XML led each. The six LED are direct drive. If aim properly it is not too bad. However there are spillage as tthe houses are shine from the spill. You can see some of it by looking at the white colored house and sidewalk on the right side. Note: My Contour video camera does not show the full effect because it does not take night exposure to good. This video sample is actually under exposed and than what is shown.

http://www.youtube.com/watch?v=rVbsk3wF1v4

I do get some cars from a distant flashing their highbeam back at me sometimes when I run this setup but not as often as I expected. Anything less than this sample such as at about 2000 to 3000 OTF is not a problem.