I've had the 24-70 2.8L for a couple of years. I've used it with my 10D and now my 1DMKII. It is on my camera most of the time unless I'm using my 70-200 2.8L IS lens or one of my other ones. The lens is sharp, has great contrast, fast focus response time and is really great in low light. It's well built and light, so it's easy to use during a day of shooting. Because of the amount of glass in the front element, be sure and use the lens hood to prevent light flare and also to help protect it.
Yes, some people have had to get their cameras calibrated. It's usually not the lens but the camera that is not focusing right. And you have the problem no matter what lens you use, but when you shoot at a very shallow depth of field at 2.8 it's going to show up more than it would with a lens that only opens up to 4.0. Also, that is the problem a lot of people have, not a focusing problem, but getting use to the shallow depth of field of shooting at 2.8. If you shoot at it's closest focusing point at 2.8, you have a very very narrow depth of field. It sometimes takes awhile for people to get use to this if they haven't shot at the wider apatures before.
The lens is great and I love mine. I've talken a lot of pictures with it and as long as I do my part, they come out tack sharp.
Mike
|