Help Needed Please - Canon 600 II & 2x III extender

[Mark Jones]

I just got a new 600 II lens to go with my Canon 1DX. While micro adjusting all my lenses today I found the 600 II will not auto focus with the 2x III extender. AF works fine with just the 600 II and also with the 600 II + 1.4x extender. AF also works fine with my 70-200 + 2x extender and 300mm +2x extender. The no AF problem only exists with the 600 II + 2x extender combination. I am using v1.1.1 firmware on my 1DX. The Canon website link says this lens combination should AF?

Am I missing something here? Given AF using the 2x extender works with two other new lenses, I'm concerned my 600 II may be faulty.

Any thoughts?

Many thanks,

Mark

[arash_hazeghi]

600 II + 2X III focuses fine with 1DX firmware 1.1.1. Maybe you did not install the firmware correctly or maybe you are using off-center focus point which would be disabled with the 2X.

[Richard Mc Donald]

See this blog post by Artie ...

http://www.birdsasart-blog.com/2012/...d-x-detective/

Richard

[Mark Jones]

Thanks for the link Richard. My 1DX came with v1.1.1 preinstalled but I've downloaded another copy and will overwrite the present one later today.

Cheers.

[Mark Jones]

I downloaded v1.1.1 firmware from the Canon USA website. After overwriting the v1.1.1 firmware that came with my 1DX already installed, I'm finding AF now works as it should with the 600mm II + 2x extender combination. Interestingly, I also sent an email to Canon USA asking for assistance at the same time I posted my original message here. Yesterday I received a reply from Canon USA stating, "Unlike some other models, the focusing system in the EOS-1D X is sensitive to f/5.6, not f/8. Autofocus will not be possible." Clearly this information is completely false and someone else at Canon has since replied in kind. Thanks to fellow BPN members for explaining and clarifying things properly.

Cheers,

Mark

[arash_hazeghi]

I downloaded v1.1.1 firmware from the Canon USA website. After overwriting the v1.1.1 firmware that came with my 1DX already installed, I'm finding AF now works as it should with the 600mm II + 2x extender combination. Interestingly, I also sent an email to Canon USA asking for assistance at the same time I posted my original message here. Yesterday I received a reply from Canon USA stating, "Unlike some other models, the focusing system in the EOS-1D X is sensitive to f/5.6, not f/8. Autofocus will not be possible." Clearly this information is completely false and someone else at Canon has since replied in kind. Thanks to fellow BPN members for explaining and clarifying things properly.

Cheers,

Mark

I'm glad it worked. The general Canon USA tech support is not great. They do not have enough training with high end gear and usually not familiar because they deal with mass market products mostly.

To get the best support/service sign up for CPS membership, you get US-based phone support and they are generally very knowledgeable. I have always been happy with them.