Canon 70-200 f4 with Canon Extender EF 1.4X III ???

I have a friend who is using the 75-300 lens, and he is realizing it isn't that great. He told me it is soft at 300mm.

He ask me about the 70-200 f4. I told him that everything I hear about this lens is that it has stellar pictures from end to end. Also, it is priced very good for an L lens.

Then he wanted to know if you can use the Canon 1.4 extender with it. Is it usable? Does it auto-focus? I told him I don't know, but I thought I would throw it out here for feedback.

It will AF with a 1.4X. (No AF with a 2X, except 1D series and 3DIII with the correct firmware.)

jimewall wrote in post #17061138
It will AF with a 1.4X. (No AF with a 2X, except 1D series and 3DIII with the correct firmware.)

Thanks jimewall,
Do you know what the f-stop will be pushed to for this combo?

guntoter wrote in post #17061168
Thanks jimewall,
Do you know what the f-stop will be pushed to for this combo?

4 * 1.4 = 5.6

Easier to just think of a 1.4X giving an additional stop, so f/5.6 (rather than using the calculation given above by yourlefthand)(FWIW a 2X is 2 stops). A maximum of f/5.6 is where Canon causes unaltered lenses to disable AF (except 1D series and 3DIII with the correct firmware).

Keep in mind a f/4-5.6 lens with a 1.4X still AF, because the lens still has f/5.6 as the max aperture (f/5.6-8).

Thanks guys for the info.

jimewall wrote in post #17061138
It will AF with a 1.4X. (No AF with a 2X, except 1D series and 3DIII with the correct firmware.)

It will however AF in live view with a 2x.

crofter wrote in post #17061261
It will however AF in live view with a 2x.

In what kind of light?

How is AF Accuracy?

How much loss of AF speed?

IQ quality?

I prefer using the right lens, but have tried with only my long zoom, but you can also tape the pins on some TCs and it keeps AF - Sort of! The above stink for most lenses, and there has to be excellent light (and contrast). My guess (haven't tried) the same is for LV.

Here is an example of 70-200mm f/4 IS + 1.4x II on a 7D (full AF, of course):

IMAGE LINK: https://flic.kr/p/o5LP​7c

ldn323 wrote in post #17062340
Here is an example of 70-200mm f/4 IS + 1.4x II on a 7D (full AF, of course):

IMAGE LINK: https://flic.kr/p/o5LP​7c IMG_0831 by ldn323, on Flickr

(The original picture looks much sharper than this. I do not know what on Flickr that causes this IQ degradation)

Hope this helps.

I will have to show my friend this pic. Great job.

This one with 70-200 f/4 IS with Canon 1.4x III TC

IMAGE LINK: https://flic.kr/p/oe2C​Bi

herculeorama wrote in post #17062988
This one with 70-200 f/4 IS with Canon 1.4x III TC

Velavadar_4452 copy by jhsurti, on Flickr

That is impressive.

jimewall wrote in post #17061198
Keep in mind a f/4-5.6 lens with a 1.4X still AF, because the lens still has f/5.6 as the max aperture (f/5.6-8).

No. First of all the Canon 1.4× extenders III are not compatible with any 4-5.6 lenses. You'll find a compatibility chart here at B&H.

Second, on variable aperture lenses the aperture at any given focal length counts, not the aperture at widest focal length. So a 1.4× might work at shortest focal length at f/4 (=5.6 with 1.4× extender) but it goes over 5.6 fast on zooming in.

This (all 70-200mm zooms actually) is one of the few zoom lenses that will really work quite well with a 1.4x t-con!

JWdlft wrote in post #17064185
No. First of all the Canon 1.4× extenders III are not compatible with any 4-5.6 lenses. You'll find a compatibility chart here at B&H.

Second, on variable aperture lenses the aperture at any given focal length counts, not the aperture at widest focal length. So a 1.4× might work at shortest focal length at f/4 (=5.6 with 1.4× extender) but it goes over 5.6 fast on zooming in.

CyberDyneSystems wrote in post #17064200
This (all 70-200mm zooms actually) is one of the few zoom lenses that will really work quite well with a 1.4x t-con!

Agreed for Canon TCs (all not just MKIIIs), but you can use a Canon TC on pretty much any lens if you add a extension tube (yes you lose infinity focus). Also Canons Life Size Converter fits all Canon but EF-S lenses (It is bassically a TC-ET combination with no front protrusion like other Canon TCs).

But my posts were generic, only the OP and you two (in these two posts) mentioned the Canon TC. I just answered the OP's question based on 1.4X and 2X TCs. Off brands TC do fit all EF (not EF-S) lenses, those were what I was basing my statements against).

Keep in mind the Sigma 150-500mm f/5-6.3 DG OS and Tamron 150-600mm f/5-6.3 VC focus through there entire range, and the high end is over 5.6. I suppose the lens may trick the camera, but they report correctly.

I assumed (not always good) that the ability to AF was based off of the lowest aperture on the lens. The reason for my assumption is anytime I've tried a TC on those kind of lenses, if the wide end auto-focuses then the tele end (even if beyond f/5.6) also still auto-focuses. Note: I've only tried it with the Sigma 10-20mm f/4-5.6 and the Canon 70-210mm f/3.5-4.5 - but they auto-focus through the entire range. Again it is a guess/assumption, but I don't truly know.