# Question about the 1.4 teleconverter iii and the 100-400 F4-5.6 L



## steven kessel (Mar 17, 2013)

I have a 5D Mark iii. My go to lens for bird photography is the 100-400 F4 - 5.6 L IS. I'd like something with more reach but can't afford any of the longer focal length L series lenses. I've tried the Sigma 150-500 on the camera and I'm unimpressed with that lens.

I was looking at the B & H website tonight and it states that the 1.4 teleconverter will autofocus the 100-400 F4-5.6 L on "professional cameras." They don't define the term and I'm unclear what that means. Is the Mark iii a "professional camera" and will the 1.4 teleconverter autofocus the 100-400 on that camera? 

Anyone out there have a clue?


----------



## rpt (Mar 17, 2013)

steven kessel said:


> I have a 5D Mark iii. My go to lens for bird photography is the 100-400 F4 - 5.6 L IS. I'd like something with more reach but can't afford any of the longer focal length L series lenses. I've tried the Sigma 150-500 on the camera and I'm unimpressed with that lens.
> 
> I was looking at the B & H website tonight and it states that the 1.4 teleconverter will autofocus the 100-400 F4-5.6 L on "professional cameras." They don't define the term and I'm unclear what that means. Is the Mark iii a "professional camera" and will the 1.4 teleconverter autofocus the 100-400 on that camera?
> 
> Anyone out there have a clue?


I have that same combination. It does not AF! I believe Canon are to release an upgrade to the firmware in April fixing it like they fixed it for the 1DX. 

*Edit:* It does not focus with live view either...


----------



## Rat (Mar 17, 2013)

rpt said:


> I believe Canon are to release an upgrade to the firmware in April fixing it like they fixed it for the 1DX.


That's correct, check http://www.canonrumors.com/2012/10/canon-eos-5d-mark-iii-firmware-adds-hdmi-af-upgrades/.

Also, the phrase 'professional camera' is traditionally used for 1D series dslr's only, as they used to be the only ones to use AF with lenses as slow as f/8 (such as the 100-400/1.4x combo). Now, the 5D3 and (allegedly) the 6D are getting this functionality too, but that doesn't make them 'professional', at least not in the Canon nomenclature, I think.


----------



## RGF (Mar 17, 2013)

at F8 autofocus is difficult for many camera bodies. Need a bright contrasy subject for the autofocus to work. Works on my 1D M4 (500F4 + 2x - but only on center focus point, some times)


----------



## Mt Spokane Photography (Mar 17, 2013)

The newest Kenko 1.4X TC works very well with a 5D MK III and the 100-400mmL. However, we are still waiting for Canon to deliver the updated firmware for the 5D MK III that extends AF to F/8.



You can be certain that AF performance will drop a lot, so for birds in flight, it might not work well. If there is ever a 100-400mmL MK II, it may be like a 70-300L which doesn't accept TC's.



If I were going to buy one again, I'd consider the Kenko, it costs less and has no physical interference with most lenses, if not all. Its very good, but not equal to the new Canon TC's.



However, some believe that a TC that works on a lens is better than one that must sit in your bag because it won't physically attach.


----------



## AlanF (Mar 17, 2013)

The Kenko Pro works with the 100-400mm on the 5DIII. The Kenko freezes the 5DIII when attached to the 300mm f/2.8 II and requires battery removal to restart the camera. As written by others, a firmware upgrade is due next month that will allow the 5DIII to autofocus at f/8 with Canon TCs.


----------



## expatinasia (Mar 17, 2013)

Mt Spokane Photography said:


> If I were going to buy one again, I'd consider the Kenko, it costs less and has no physical interference with most lenses, if not all. Its very good, but not equal to the new Canon TC's.



True. And the Canon's is "Dust and Water Resistant" which may be an advantage to some.


----------

