Canon 1.4x Extender III with 100-400 L IS Lens

[Warrenden]

Hi all

I have just purchased an 100 - 400 L IS lens and am considering buying a Canon extender, but people tell me it will not autofocus with my Canon 5D Mk2 has anybody used this combination.

Thanks

Phil

[colintf]

Re: Canon 1.4x Extender III with 100-400 L IS Lens

Hi all

I have just purchased an 100 - 400 L IS lens and am considering buying a Canon extender, but people tell me it will not autofocus with my Canon 5D Mk2 has anybody used this combination.

Thanks

Phil

that is correct, I belive it wont autofocus at the longer on the 5d2

[DrJon]

Re: Canon 1.4x Extender III with 100-400 L IS Lens

The 5DmkII will only focus down to f5.6, the extender adds a stop of light loss so anything over f4 won't auto-focus. However it might focus in live-view, but that's so slow I suspect it would be impractical.

[colin C]

Re: Canon 1.4x Extender III with 100-400 L IS Lens

As auto-focus is relatively new in photographic terms, we always used to focus manually. Not a major problem focussing manually.

[Stan]

Re: Canon 1.4x Extender III with 100-400 L IS Lens

I have just purchased an 100 - 400 L IS lens and am considering buying a Canon extender, but people tell me it will not autofocus with my Canon 5D Mk2 has anybody used this combination

there is the trick of taping the pins to fool the camera into autofocus but again it is so slow and, when i had a 100-400, I tried it out and the quality was rubbish as well

Stan

[jk224]

Re: Canon 1.4x Extender III with 100-400 L IS Lens

As auto-focus is relatively new in photographic terms, we always used to focus manually. Not a major problem focussing manually.

The manual focus cameras I started with had a micro-prism in the viefinder to make focussing easier, most d-slrs don't have these.

[colin C]

Re: Canon 1.4x Extender III with 100-400 L IS Lens

The manual focus cameras I started with had a micro-prism in the viefinder to make focussing easier, most d-slrs don't have these.

Agreed, but for wildlife and motorsport, we used to change the micro prism screen for a matte one, as it made life a lot easier. If you concentrated on the micro prism, you tended to lose shots, but with the matte screen, you could concentrate on the action and with a little experience, still focus.

[Warrenden]

Re: Canon 1.4x Extender III with 100-400 L IS Lens

Hi all

Thanks for all the advice and I will stick with manual focusing, but do I go for a 1.4x or a 2x for 100-400.

Many thanks

Phil

[colin C]

Re: Canon 1.4x Extender III with 100-400 L IS Lens

The 1.4x.

[Cyberman]

Re: Canon 1.4x Extender III with 100-400 L IS Lens

Just looking at the impact on aperture I'd think 1.4x.
Indeed it's a question I've asked myself as considering one.

[Riggers]

Re: Canon 1.4x Extender III with 100-400 L IS Lens

Definitely 1.4 on that lens. I have the 300 F4 and I'm going to try a 2x which will give me 600mm at F8, similar to yours which will be 560mm at F8 if you use the 1.4.