Elliot - No special lens for the shot. I simply placed my old digicam on top of a Gatorade bottle with the timer set.
As far as a preferred tarp setup is concerned I would state that I've found various configurations work best for different situations. On dry, wind-less nights such as the situation was here, I pitched the front of the tarp on the top of the pole, the back at mid-height and the sides roughly a foot off the ground.
In a storm situation I would drop all he above settings at least a foot down. If windy/cold conditions were present I would drop the windward side down.
I hope this is helpful. Feel free to post more questions, as there are some very experienced tarp campers here at BPL.