Canon 2x and 1.4x mk3 extenders

[wopbv4]

Well...darn, now I need a 12mm extension tube...  If it works the same, that means the 1.4xIII-EF12-2xIII combo behind a 600/4 will give me 1680mm that reports as f/8 and will AF on the 1D X. 

I tried :
1DX, 2XIII, 12mm Kenko, 1XIII, 70-200 F2.8 L II @200mm.

Manual focus works, but autofocus ( single spot AF in the center) does NOT. I tried to focus on infinity, 10 m, 5 m, none of them focussed.

I might be doing something wrong?

[wopbv4]

sorry for the typo
should be:
1DX, 2XIII, 12mm Kenko, 1.4XIII, 70-200 F2.8 L II @200mm.

[ietion]

as far as i've tried, autofocus on extenders only works on primes. Might not apply to all, but I think that's your problem. Try them with a prime.

[neuroanatomist]

The OP had the 1.4x closest to the camera.

[wopbv4]

Ok, I missed that.
I tried with 1DX, 1.4XIII, 12mm Kenko, 2XIII, 70-200 F2.8 L II @200mm, still no joy.

Even if I manually focus first and then press the shutter button halfway, it still hunts and is unable to acquire focus.

It is night in Oz, but I switched all the studio lights on (=a lot) and sufficient distance around 10 m (=manual focus works) at a high contrast subject, it still hunts like mad.


I will try in daylight tomorrow morning, but I have little hope.

Anyway, it works in manual mode, so thanks for the the tip !!


Hope this informs

Ben

[Alex]

Thats really strange because mine works fine... I tried it earlier today in the garden with random stuff and it was a little slow but still worked... Have you tried it on Live view?

[wopbv4]

Hi Alex,

indeed in liveview it works, all be it very slow and the target needs to have a fair bit of contrast.
Anyway, from now on , I will carry a 12 mm extension tube, so I have the option to combine the extenders.

Thanks everybody !

Ben

[Alex]

Glad I have finally contributed something worthwhile to this forum