Hello all! I have been hired to take portraits at an upcoming prom, and I am weighing my options as to how to light them. In the past when I've done this, I've used 3 speedlights (2 in clamshell setup and a third on the background). I currently have an Alien Bees AB800 with a 48" octa, as well as an ABR800 ringflash with the 30" moon unit that I plan to use, and several speedlights I can add as well.
I think these will probably be full length shots. I've had pretty good success with lighting large group portraits using just the AB800 in the octa, cranked up pretty high, directly above camera, without too much fall-off, so I don't anticipate any problem with this being enough to light a couple, although it may be a little flat. I have not used the ABR800 off-camera in the moon unit for anything yet; I mainly use it in a photobooth setup with the camera inside it, true ringflash style.
Anyone have any experience with the ABR800 in moon unit, off camera? Would it make a good background light? Should I make a clamshell out of the two instead, and light the background with a speedlight? Just trying to weigh the options for the most interesting light vs tried and true flat light out of the octa.

