ashmadux

Let me qualify my statement a bit. The 70-200mm is the best zoom canon lens I have owned. If your version isn't working with your AF system, sending it back is what I would do as well. It has always been my opinion that if you spend $2,000 for something it should work as intended.

What a camera needs and does not have is the ability to do a AF manual adjustment at both ends of the zoom range.

When I did my testing I did over 1000 shots. The focus curve I spoke about seems to be S shaped, meaning in the center ranges it is less noticeable, and feathers off abruptly when your at the widest and longest. I suspect that it is just the nature of this lens and just how the mechanics work. Even though it works like this, in real life situations it was not significant enough that I ever notice. When I say it is off I mean it has a bias for the DOF to shift toward that direction. You should be getting super sharp results, I do with mine. I wouldn't discount the lens because it works this way. Each lens has its own unique properties, and if you know those properties you can work the lens to its potential.

You should know also by looking at the charts that the 70-200mm is at its sharpest at 200mm, and less so at 70mm.