Originally Posted by
GrumpyDiver
Given the dark conditions you are planning to shoot in, I rather doubt that shutter speed will matter at all. Your flash duration will be in order of 1/1000th sec, which should be more than sufficient to freeze the dancer. As long as there is little or no ambient light, your shot won't be affected.
If you have the Elinchrom; and I'd probably forget about the SB900 units. I'd work with it and a large softbox to keep the light spill down, to start with. I'd set it up high and in parallel to the path of the dancer to start with. I've never shot with smoke in this type of scene and am pretty sure it is not going to add much, so I'd get the shot I was after nailed before getting any smoke on the set.