Canon EF 200mm f/2.8L II USM + EOS 6D Focusing Issues

Steve Balcombe wrote:

Onky wrote:

No matter how I focus, using AF or manually, the focus plane is always considerably closer to the camera:

There are actually three distinct ways to focus - AF when using the viewfinder, MF when using the viewfinder, and Live View focusing.

Viewfinder AF uses the autofocus sensors in the bottom of the mirror box, and this can require calibration.

Manual focus using the viewfinder relies on the focusing screen at the top of the mirror box below the viewfinder. On rare occasions this can be misaligned.

Live View focusing uses the image which falls on the sensor, so it requires no calibration and is essentially guaranteed to be correct. There is no fundamental difference between Live View AF and Live View manual focusing which is why I've lumped them together.

As I said, Live View focusing is guaranteed to be correct so the first thing to do is give that a try. Manual or AF should give exactly the same results (if not, it's operator error!).

Then try conventional manual focus through the viewfinder. This should also work - if not (and barring operator error again) you have a problem with your focusing screen which is not user-serviceable.

Then, irrespective of the viewfinder MF result, try viewfinder AF. If this gives a result which is different from the Live View result, it is possible that AF microadjustment could help.

Thanks, everyone! I did the adjustments today (+13 or so), and that helped noticeably. Manual focus gives somewhat better results, though.