2x converter for the 100-400L

Does anyone know of a 2x tele converter that will work with the 100-400L canon lens.

It'll work but you'll lose autofocus.

Yeah, no autofocus. It will f/9 at the short end, and f/11 at the long end. I don't believe that even a 1D body will AF w/ that.

If by work,you mean AF,I dont think any of the Canon cameras will AF with a 2* TC on that lens,the 1 series will AF at f8 but the others wont.The 2* tele adds 2 stops so the lens becomes f11 at 400mm .If you dont want AF most TC's will MF but I suspect the IQ is a bit iffy.

Thanks for the replys.

Confused. Is this because of TC or camera don't AF for F8 and beyond?

PR

underwrap4u wrote in post #11541357
Confused. Is this because of TC or camera don't AF for F8 and beyond?

PR

Camera will not allow autofocus past a certain f stop. The TC alters the amount of light coming through the lens, and informs the camera of the presence of the TC.

I tried taping the pins, and the camera (50D) would try to auto focus, but it just could get the job done really. Too slow and inaccurate. Manual focus is the only way with that lens and TC combination.

I have spent some time with the 100-400L and the Canon 2x TC, and I finally came to the conclusion it's a tough way to get photographs, especially wildlife photos or anything that doesn't just hold still. With really good light and a sturdy tripod it isn't impossible to get usable photos, but the IQ takes a big hit and the keeper rate drops like a rock, in my opinion.

I read somewhere recently that the new 1.4x III now allows the AF and IS to function on the 100-400L. Is anyone shooting with this combo that can verify? Thanks.

troutfisher wrote in post #11541177
If by work,you mean AF,I dont think any of the Canon cameras will AF with a 2* TC on that lens,

The 2X on a 7D body will AF nicely with the 70-200 f/2.8 IS, however. I've given up trying to get any TC to work on the 100-400 - I can't manual focus worth a darn.