thanks everyone for the comments. I agree it is underexposed, but that is not without good reason. my lighting equipment for this picture was 2 desklamps. to stop the smoke and get a proper exposure was a virtual impossibility, unfortunately. I finally have a proper strobe, so I might try a similar shot again.
as for the crop, I considered a vertical frame, but I quite like the empty space to the right. Different strokes for different folks, I suppose.