I shot these with the 40D on a tripod. I put the camera in manual and set the it from f8 to f16. I had the shutter speed set in bulb mode. I was using a shutter release and mirror up mode. I would just hold the release down for a couple of explosions and then let go. I had to watch to make sure I did not get too many bursts that they would overlap too bad. I think they turned out fairly well for a first time.

To see more please take a look on my flickr set.