I shot this in my front yard late at night. I set up a constant light on the left side and exposed it just enough to see the motion, but not the background. I then set up an AD600 in a soft box camera right (strobe). I set the camera on a slow shutter with rear curtain flash and had her dance into the strobe from left to right as soon as I hit the shutter. Then I had her stop in the final pose to get the flash to hit exactly on that pose. This took about 20 tries to get it how I wanted it.