Canon EOS 5D mk II and 100-400. Converter ???

Hello all, I can't seem to find a definite answer to this question.

Which extender's auto focus will work with a EOS 5D mkII and the Canon EF 100-400mm f/4.5-5.6L IS USM, without having to mess around with taping here and there.
I have tried the Canon 2X II but it is difficult to keep a moving object in focus, and I cannot afford a L-series lens yet as my lotto number's have not come up yet...

I am mostly photographing aircraft, so any ides would be helpful.

http://www.flickr.com/​photos/mcdee6174/

Thanking you

You need a minimum aperture of 5.6 for auto focus to work correctly. When adding a 2X to that lens it turns into a 9-11.2 aperture lens.

Hope that helps

why not switch your 5D MK II for a 7D...based on your flickr, i don't know if you really need a full frame camera, and the 7D should have better AF for fast movement, and will give you a crop factor of 1.6X, so it'll give you more pixels on target

i don't think you'll find any 2X TC that'll retain AF, and even a 1.4X probably won't keep it well enough to work for flying planes

as far as I know, neither will AF with the 5d Mark2...If you have the 1.4x and a 1d body you will retain AF on the 100-400.

TheBigDog wrote in post #13274030
as far as I know, neither will AF with the 5d Mark2...If you have the 1.4x and a 1d body you will retain AF on the 100-400.

Correct. You MIGHT get some level of AF working by taping pins/using third party, non-reporting TCs, but the performance even then is likely to be pretty sluggish.

TheBigDog wrote in post #13274030
as far as I know, neither will AF with the 5d Mark2...If you have the 1.4x and a 1d body you will retain AF on the 100-400.

Sad but true. This is one feature that would make me upgrade my camera body.

Fingers crossed.

DreDaze wrote in post #13274025
why not switch your 5D MK II for a 7D...based on your flickr, i don't know if you really need a full frame camera, and the 7D should have better AF for fast movement, and will give you a crop factor of 1.6X, so it'll give you more pixels on target

i don't think you'll find any 2X TC that'll retain AF, and even a 1.4X probably won't keep it well enough to work for flying planes

I agree. Took a look at your Flickr and don't really see the need for full frame.