I built one out of a .50cal ammo can, solar panel, landscape "up light", 2 12v feeder batteries, and a remote control for car/motorcycle accent lighting. I have less than $100.00 into it and it illuminates out to about 75 yards. I place the light down on the ground 10 yards away and when I hear the hogs at the feeder I hit the remote. Constant burn time is only about 40 minutes as I am using a 50w halogen bulb and not led's, so hence the remote and waiting in the dark until I hear them (not to mention you do not want to deep cycle the feeder batteries).
I will try to get some pics up of it.