Northstar said:
I've read that the AF speed is good, but not as good as the big primes....which has me questioning weather I want this lens for shooting sports/action....any thoughts?
I got it for sports primarily. I am shooting HS football this thursday, so I will find out. I will use it on a 1DX so I don't think the loss of a stop (from 2.8 on my old 400) will be much of an issue, but I expect to get a lot more usable shots from the zoom. I think the difference in focus speed is on par with my old 400. I am sure the difference between it and the new super teles is only milliseconds and wouldn't be noticeable.