Brand New 5D mkIII Bizarre viewfinder issue

[Kenan171]

I have a brand new 5d MKIII, that arrived today. I took it out of the box, and put my (also) brand new 24-70 L series on it. Looking thru the viewfinder, I cannot get the lens to manually focus. I try the lens on a different body, it's working properly. I try adjusting the diopter of the viewfinder. It makes no difference.

Ok, I think, I'll try autofocus. I put a battery in the camera and boom!, everything is pin sharp. Great, I think, so I adjust the viewfinder using the focus points then take the battery out to continue charging it. Instantly, the problem returns.

Does anyone have any idea what's going on?

Thanks!

[MikeSowsun]

 "Canon warns that removing the battery while the camera is writing to the card could result in corruption of data".

Where does it say that? I couldn't find it in the 5D Mk III manual. 

[cale_kat]

Page 33, gray "warning" box at the bottom of the page.

But really, this is basic stuff. Good electronics/computer practices have always included "ejecting" cards and ensuring that nothing is writing when power is shut down.

[MikeSowsun]

Thanks, I hadn't seen that before.