Non reporting teleconverters

[Brian G. Irving]

Hi everyone

I have recently added a Canon Ef 100-400mm F5.6L IS to my collection of Lenses. Can anyone tell me if the non-reporting Tamron or Kenko 1.4X TC will or will not AF on the 7D.

Thanks

Brian

[Nancy A Elwood]

Brian I would not recommend any TC for this lens. As with the Nikon 70-300VR, TC's just make these lens too slow and would decrease the quality markedly.

[Jeff Cashdollar]

Brian,

I have heard they will to some extent but are problematic. IMO 4x zooms are not the best lens for TC's and agree with Nancy.

[Christopher C.M. Cooke]

Brian I would not recommend any TC for this lens. As with the Nikon 70-300VR, TC's just make these lens too slow and would decrease the quality markedly.

I agree %100

[Stan Cunningham]

Brian,
I'm sorry to tell you I can't get any of the teleconverters to AF on my 100 - 400.
I have a Tamron 2x, that's for sale on ebay now, and tried a Canon 1.4 from BandH and sent if back as I couldn't get it to work either. I love the lens, but I can't push it beyond the 1.6 crop factor.
Maybe yours will work as I heard some will, good luck.
And bandhphoto.com will take items back if they told you they will work and they don't.
Stan

[Kaustubh Deshpande]

I have tried the cheapo tamon non-reporting 1.4x for my 400 f5.6L on 40D. AF is slightly better than than the canon 1.4x( with taped pins offcourse). But not even close to bare lens focussing. And I am talking only about one-shot. Forget using ai-servo. At f/8(wide-open), the IQ is not very good. at f/9, it does improve...but stll not as good as Canon TC. For hand-held work, I dont find any TC useful with this lens-cam combo. Since you have IS, it might work. Best thing to do would be use tripod, live-view and MF.

Unfortunately, to get to good quality 500+ focal-length + AF on 1.6x crop camera, no cheap option. cant beat the system :-)

[David Smith]

I am using the Tamron 1.4X TC on my Canon 100-400 5.6L as I type this, and maybe I just got a good one, but my 100-400 is AF fine with the Tamron TC. I have the lens and TC on a 40D.. It does not appear to focus quite as fast as the bare lens, but fast enough. I am in the HS Al-Servo mode.

Dave

[Nancy A Elwood]

Dave the quality is what matters and like has been said no cheap way out. The 100-400 is a great lens on its own, but for more reach, the wallet must be reached for. I suppose it depend on what you will accept quality wise.

[David Smith]

Nancy:

I can understand that.. I also have a 300 2.8L IS lens and a 500 f4 IS lens. I was just trying out the 100-400 w/ 1.4 TC in response to this thread..

Cheers..

Dave