Since yer online, Doc, here are a few of the results of your suggestion. The camera would not allow me to shoot at 1 10th, even with 100 ISO. I had to settle for 1/30th-1/60th, but at 400mm effective focal length, there was more than sufficient panning blur. It sure made it easy to thin the herd. Only about 1 out of 12 keepers. But that's not the only thing I shot. I got some other stuff...including one that shows the effect the wind was having on my camera. It was blowing from right to left...made the track greasy as hell for the drivers, but they did a fairly good job of staying on the track.