Just a thought. How do studio flash users trigger their studio flash ? I always used my Canon 10D and 5D cameras pop up flash that fires 2 flashes to trigger the studio flash using my gizmo. But having purchased a Nikon D90 I find to my horror that this camera fires 3 flashes from the pop up flash. So it was back to the drawing board to design another gizmo. This works OK now with the D90. It was just a thought that crossed my mind.