I had a strange experience this morning. I put a Tamron 28-75 f/2.8 on my 40D and started shooting the guys warming up for the basketball game. Several times the message "busy" would appear in the bottom panel in the view finder. My only guess is that the lens was hunting. AI didn't take too many shots because I didn't like the results is was seeing on the LCD. So, I put it away. I did take a few at ISO 3200, f/2.8 and 1/320 and they were still a little under exposed so I was glad I had the strobes to use instead of shooting ambient.
