I'm more concerned about WHY you have an 8 ft tall Gort laser monster!
Seriously - you trying to re-shoot your own version of "The Day the Earth Stood Still" or something? (Or are you just trying to scare the piss out of the neighborhood kids? Because if I saw that thing in someone's backyard in the middle of the night, I'd probably shit myself.)
The video looks good, but it appears that the beams are no more than 10 ft off the ground. Eric was talking about a maximum altitude of 150 feet. That's a big difference. Even 50 feet is probably too high. I think you could work with 20-30 feet though.You are right about controlling fog outside, but if it is a quiet night you can get some spectacular effects, as seen in this video:
How much power did you use for the effects seen in the video?
Adam