CANON 1.4 Extender III ?

[Lakelord]

I’m considering buying a CANON 1.4 Extender III but am slightly confused after reading some reviews.
The CANON website states “The extender's design ensures there is no loss of lens performance or image quality” however, I have read Customer reviews that state the AF no longer works with this in place?
So, question is, can anyone verify whether the AF (and IS for that matter) will or will not work with the extender?
It will be predominantly used with an EF 100-400mm f/4.5-5.6L but will it also work with non ‘L’ lenses. I’ve looked for a compatibility chart on the CANON website but cannot find one so if anyone has any info on this, that would be appreciated too.

[nellyleelephant]

Depends on the body.

Unless you're using a 1 series or 5D3, you will lose AF with that combo (all other Canon bodies need f5.6 or faster to AF)

As far as other lenses go, no. L lenses only, and not all of those. I think the 70-300L has issues.

[DavidCane]

I believe the AF with a 1.4x will only work on an 'L' lens f/4.0 or faster, unless you have a 1D body.

Likewise a 2x extender AF will only work on an f/2.8 or faster lens unless you have a 1D body.

[nellyleelephant]

DavidCane said:

I believe the AF with a 1.4x will only work on an 'L' lens f/4.0 or faster, unless you have a 1D body.

Likewise a 2x extender AF will only work on an f/2.8 or faster lens unless you have a 1D body.

.....or a 5D3......

[2slo]

TCs don't affect IS. AF has been covered above correctly. The cheapest new option if you want f/8 AF is the 5D3 which is an excellent camera. That would pair with the 300mm f/4 L which is very good value and would then work with the 2X TC III to give a 600mm f/8 lens.

[Lakelord]

Thanks everybody. I've a 7D so I guess that means I give it a miss or have to MTFU and start to focus manually?

[nellyleelephant]

I think some non reporting teleconverters (non Canon) will still AF, but don't expect too much speed or accuracy.

[nellyleelephant]

Guam said:

^^^^

This once the firmware is updated, Just bought the Body with a 2 X converter for my 100-400l Based on that update, mate of mine updated reckons it works well now

Won't that be f11 though? Don't think that will AF.

[nellyleelephant]

Guam said:

It will AF once the firmware is updated, he has tested it and works fine. I looked at the details on the update <info at home so cant link> and it clearly states AF with the 2 X converter <and the 1.4>.

A 2x will work with a 5D3, but only if the max max aperture is f8 or larger, so with a f2.8 lens it will be fine. I used to use a 1.4 and 100-400 on a 1D2N which took the aperture to f8. A 2x will take it to f11.

[DibblyDobbler]

OP - I've a Kenko 1.4tc which I use with a 400 f5.6 and it works very well (previously used it with a 100-400 - worked fine with that also). Autofocus + decent IQ. Make sure you get the right one though - it's a Pro 300

ETA - should have said this is on a 6D, should work fine on your 7D also I think

[RobDickinson]

Remember though a 1.4 on a 5d3 gives you similar reach to the bare lens on a 7d.

I personally wouldn't bother with one on the 100-400.