I managed to get my hands on a Canon 300 F:2.8 L series lens for a few days and decided to see what I could get done with my running dog. The light was not ideal, and the location didn't have a very good run up section. I shot about 150 frames or so and got these six (yes I said 6) that were pretty close to what I was attempting. The focusing abilities of lens/camera combination doesn't seem able to quite keep up with the fast running dog, but on occasion does nail it. I hope we get some better light while I still have access to the lens, and I wonder if I would be having better success with a higher end camera body. I am shooting a Canon 30D which is about 3 generations old. Here they are. All shot at F:2.8 and ISO 400; shutter speeds were 1/1600th, 1/1250th, 1/1000th, 1/1000th, 1/1000th, & 1/640th.