Has anyone experienced some more than usual shaking when the IS is initiated. I know when I first got the lens that it has some very tiny moving of the picture when IS first start, which isn't very noticiable. But recently when IS starts up, especially when the focus distance has dramatically changed, I can see large up and down motion of the picture in the viewfinder going up and down. It does stablize and shoots normally, and once IS is running, taking more shots is fine.
I'll probably send the lens to Canon to get fixed but wanted to see if anyone has experienced this. Also alot of dust has accumulated inside the lens, so hopefully I get that cleaned as well. But so far it hasn't affected image quality though. I'm wondering if the dust will affect the gyroscopes of the IS system. I'm sure they are very sensitive, but I'm not sure what to make of it.
