I understand. The D40 would be too slow for such moving targets. I wonder if you could accomplish what you want through the computer-control interface to the D40, if it has one. I know some Canons can be controlled from a computer. In that case, I wounder if you could script something to do the bracketing for you! Granted, it would be pretty crazy to carry a laptop with you on your photo expeditions, but I'm curious now!