http://zebralight.com/Headlamp_c_7.html
For my backyard setup I use two of these headlamps but you could get away with one for how bright they are. They use the 18650 batteries so you can get a bunch for cheap. and some of the models can look great for filming. I'm sure it's not the ideal light for a backyard setup flood light but you also get a dope headlamp