Which, if any, 2x Converters Work With 400mm F 5.6

Hi,
After much deliberation and saving I'm now in the position to finally buy a 400mm f5.6 prime. I'm a bit confused as to whether any 2x converters will work with it to retain autofocus. I've heard mention of taping up pins etc?? I'd prefer to buy the Canon one because I assume the Optical quality will be better and would prefer a 2x but would consider lower if that's easy to af. Help - (as usual ) and thanks - (as always)

Luv etc

There isn't a 2x tcon available for your 400 f/5.6 that will let you retain AF, even if you had a 1 series camera. There is a trick to get AF to work by taping over a couple of the contacts, but from what I've heard AF is pretty slow and will hunt.

All the data you need is in the tcon sticky in the lens section: https://photography-on-the.net/forum/showthre​ad.php?t=41922

The canon 2x will work with it but you will lose autofocus as the TC will tell the camera not to bother.

There are other pro quality 2x TCs out there that will allow you to maintain autofocus. However expect the lens to hunt a lot due to the low light levels that will be hitting the camera. The Canon TC is the only one that actually disables autofocus.

davewalters wrote in post #2187933
Hi,
After much deliberation and saving I'm now in the position to finally buy a 400mm f5.6 prime. I'm a bit confused as to whether any 2x converters will work with it to retain autofocus. I've heard mention of taping up pins etc?? I'd prefer to buy the Canon one because I assume the Optical quality will be better and would prefer a 2x but would consider lower if that's easy to af. Help - (as usual ) and thanks - (as always)

Luv etc

The standard Tamron 2x will have limited AF on the 350D and 300D (4 outer horizontal points only, center and top/bottom points are dead). It will also work with a 1DM2's center point. AF at f/11 in these setups will be very slow, and the subject has to be well-lit and contrasty for focus to achieve lock.

I see that you have a 30D. I don't know of any 2x TC on the 400 5.6L that will allow AF on the 20D/30D. Using a standard Tamron 2x, or taping other 2x TCs, will enable the body to attempt AF, but it's always hunting and never achieving focus lock.

Romy

Citizensmith wrote in post #2187965
The canon 2x will work with it but you will lose autofocus as the TC will tell the camera not to bother.

There are other pro quality 2x TCs out there that will allow you to maintain autofocus. However expect the lens to hunt a lot due to the low light levels that will be hitting the camera. The Canon TC is the only one that actually disables autofocus.

Are you certain the Canon one is the only one? Unless I'm reading the sticky wrong it looks like the Sigma 2x also disables AF on the 400mm f/5.6.

Kenko 2x MC4 works with my 100-400mm(No taping) and 1dmk2n...I tried asking others in the t-con sticky if the pro300 would work, but no one has responded. The tape trick sucks! When I had my 20D I tried doing it, It will hunt and hunt and focus correctly once in awhile.

Bob_A wrote in post #2188581
Are you certain the Canon one is the only one? Unless I'm reading the sticky wrong it looks like the Sigma 2x also disables AF on the 400mm f/5.6.

Sigma won't AF....

the kenko pro 300 2x converter won't autofocus w/the 400 5.6. I bought it and it will only MF w/my 100-400L (same aperture). It chages 5.6 to 8 and it has to be at least 5.6 for the camera to recognize AF...

Permagrin wrote in post #2188642
It chages 5.6 to 8 and it has to be at least 5.6 for the camera to recognize AF...

Not the 1dmkIIN

OH, gosh, you are right...I forgot that the 1 series will recognize up to f8! dummy me...

Permagrin wrote in post #2188775
OH, gosh, you are right...I forgot that the 1 series will recognize up to f8! dummy me...

Thanks for the info, looks like I might need to make a purchase

well, if it's any consolation for the previous error, the TC has nice IQ...(as well as can be expected for a 2x)

Permagrin wrote in post #2188789
well, if it's any consolation for the previous error, the TC has nice IQ...(as well as can be expected for a 2x)

I'd expect it to be better then the MC4 which I got to try out AF and what sort of length I could get. As long as you are using a teleconverter for fairly close work, even the cheapies work well. Some find it funny to strap a $1500 lens to a $50 2x...and I guess I do too, but I love the pics!