7D2 autofocusing at f8 - and not (1 Viewer)

[Steve Gantlett]

My new 7Dii seems to be autofocusing nicely, including with a Canon 1.4x ii attached to my Canon 400 f5.6 - and this is giving nice sharp results. But the same 7Dii body is completely refusing to autofocus when I attach a Canon 2x ii to my Canon 400 f4 DO. Like the smaller f5.6 with a 1.4, this also equals f8, so why won't it autofocus (it does so fine with the 1.4x ii)? Has anyone else tried this combination and does it work for them?

 

[Roy C]

That's strange Steve, I will be interested in other folk who have this combo but I cannot see any reason why it should not AF (centre point + expansion).

 

[Steve Gantlett]

My apologies. I made a mistake. My 7D2 does autofocus with my Canon 2x ii. Operator error! Sorry to waste your time. I've only tested it in very poor light so far, but so far the combination seems surprisingly sharp. Hopefully it will be usable in real situations.

 

[Mark Batten]

Steve. Do let us know how you get on with the 7D 2 with higher ISO images.

 

[davethebird]

Steve. Do let us know how you get on with the 7D 2 with higher ISO images.

Hi Mark,
The mkII is definitely an improvement on the 7D. The attached was taken at ISO 6400 and was easy enough to clean up.