Canon 6D + 70-200 F4 + 2x TC. AF maintained or not ?

[DibblyDobbler]

A quick question for any of the boffins out there: does anybody know or have an opinion on whether AF would be maintained with a 70-200 F4 + 2x TC on a 6D body ?

I'm aware that typically you'd want an F2.8 lens with a 2x TC to keep AF but I don't think it's clear cut on the newer bodies?

TIA

[markmullen]

It won't at the moment, IIRC they only AF up to f5.6 which you're going to be F8 (F4 +2 stops for the converter). That said the 5D3 won't at the moment but Canon has said the next firmware update due shortly will include AF on F8 lenses, centre point only, like a 1 series.

[DibblyDobbler]

Thanks Mark

Contemplating a 70-200 F4 IS as my next purchase (if I sell the 16-35!). I occasionally fancy doing some wildlife shooting so it would be handy to be able to use a 2x tc. I believe a Kenko Pro300 DGX might work

[markmullen]

You've got plenty of resolution, you could use a 1.4x and crop.

[RobDickinson]

As said the 6d wont focus slower than f5.6 , I doubt it would work that well at f8 anyhow, but it may be worth a go.

[2slo]

Another option would be a non reporting TC such as one of the Kenko 2x versions which would give you the magnification but doesn't electronically communicate so hence fools the camera into thinking it's not there (if that makes sense) I've even seen these stacked with a Canon reporting 1.4x TC to give an even longer FL. Very slow AF though, or liveview is available if you're after a static subject.

[DibblyDobbler]

2slo said:

Another option would be a non reporting TC such as one of the Kenko 2x versions which would give you the magnification but doesn't electronically communicate so hence fools the camera into thinking it's not there (if that makes sense) I've even seen these stacked with a Canon reporting 1.4x TC to give an even longer FL. Very slow AF though, or liveview is available if you're after a static subject.

Thanks Mark - I believe the Kenko Pro300 DGX would probably do the job.

I raised a thread on TP here which got some interesting replies.

[2slo]

DibblyDobbler said:

2slo said:

Another option would be a non reporting TC such as one of the Kenko 2x versions which would give you the magnification but doesn't electronically communicate so hence fools the camera into thinking it's not there (if that makes sense) I've even seen these stacked with a Canon reporting 1.4x TC to give an even longer FL. Very slow AF though, or liveview is available if you're after a static subject.

Thanks Mark - I believe the Kenko Pro300 DGX would probably do the job.

I raised a thread on TP here which got some interesting replies.

Yes, if you go down that route though, be careful to be very specific as to the model of Kenco TC you buy. I can't recall where I read this (maybe POTN?) but I have read that there are two Kenco TCs with similar model numbers, one is non reporting (what you want), the other reports making it useless for your needs. I did scan through the TP thread from your link and someone mentioned the upgrade coming to the 5D3, which I believe will be in March, allowing AF at f/8 and how that may be then applied to the 6D. Hopefully it will be which would help your situation. Keep an eye on http://www.canonrumors.com/

[DibblyDobbler]

Thanks again Mark

[RobbieKB]

I'm glad you asked this Mike because I wanted confirmation after our Flickr discussion .

[DibblyDobbler]

RobbieKB said:

I'm glad you asked this Mike because I wanted confirmation after our Flickr discussion .