New 100-400, no AF with 1.4 extender on 7D

Help/advise please.
I have just taken delivery of a new 100-400 L IS II and I'm very pleased with it however I cannot get AF with my EF1.4x II extender when combined with my 7D (not Mk II) but all is fine if I use my EF 300 prime instead of the 100-400. I'm not intending to use the extender generally but on occasions it could be handy. Canon's compatibility chart states it will work using centre focussing but it does not, at least not for me. I have contacted Canon and they say it should work and refer me to the above.
Any ideas?

I would be very surprised if it would AF as that is a function of the camera not the lens.
Just looked on the Canon web site http://www.canon.co.uk …s_ii_usm/#p-specification and it says will AF with 7D Mk2 nothing about the Mk1, looks like there is some duff info somewhere

Date: 16/03/2015
Service Request:1-3789913495

Dear Mr. Derrington,

Thank you for your request and for contacting Canon.

With reference to your enquiry concerning the compatibility of your EF 100-400mm lens with the EOS 7D, we can confirm that auto focus is possible when using the central focusing point only.

It won't work.

http://www.canon.co.uk …_ii_usm/#p-specification4

SPECIFICATIONS WITH EF 1.4X III
AF Possible
¹ AF possible only with EOS-1 series, 7D Mark II and 5D Mark III with firmware 1.2.1

oingyboingybob wrote in post #17477085
Date: 16/03/2015
Service Request:1-3789913495

Dear Mr. Derrington,

Thank you for your request and for contacting Canon.

With reference to your enquiry concerning the compatibility of your EF 100-400mm lens with the EOS 7D, we can confirm that auto focus is possible when using the central focusing point only.

Looks like Canon service have made a mistake. The original 7D did not have f/8 center spot focus capacity. The first camera other than a 1 series to have the f/8 feature was the 5D Mark III followed by the 7D Mark II. They are currently the only two non 1 series cameras to feature f/8 center point focus.

Alan

Has anyone anywhere ever claimed the 7D would AF at f/8? Without tricks, I mean.

GeoKras1989 wrote in post #17477147
Has anyone anywhere ever claimed the 7D would AF at f/8? Without tricks, I mean.

Not even with tricks. The early firmware 5D3's would AF with the pins taped but the 7D would not. That tells me there is a physical limitation and there is no way to make a 7D AF at f/8.

Well that clears that up then. Thanks to all who took the time to reply.

I have a 7D and I can confirm what others have said. It will not autofocus with the 100-400L and an extender. Autofocus is limited to f5.6.

Mike

One might try the Kenko Pro 300 Teleplus 1.4x converter. Although discontinued, Amazon.com has a few left at $139. I cannot speak for the 100-400L-II or the 7D, but my 70-300L does autofocus on my 70D. It does struggle a bit.

Canon's responses were confusing, to say the least. I did send another email to them following their first reply where they informed me the combination of that lens and 1.4x extender would work. The 2nd response told me exactly the opposite. I'm not particularly disappointed as to put an extender on this, or any other high-quality lens, is not something I would normally do or recommend as results can be mixed to say the least but it would have been nice to have the facility of AF and longer reach for the odd occasion where approach to a distant subject is restricted. There's always MF as a fallback though - but not as convenient when subjects are moving. I am considering the 7D Mk2 but I'm not yet convinced that it's worth the expense, particularly as a pro photographer friend of mine is currently having focus problems with hers. She's having a dialogue with Canon (Australia) so I hope that the responses she gets are a bit more consistent that I had from Canon UK.

RodneyCyr wrote in post #17477308
One might try the Kenko Pro 300 Teleplus 1.4x converter. Although discontinued, Amazon.com has a few left at $139. I cannot speak for the 100-400L-II or the 7D, but my 70-300L does autofocus on my 70D. It does struggle a bit.

I tried. It focuses, albeit not without a lot of hunting and only in bright light, but the IQ degradation was unacceptable. I could have just lived with the Sigma 120-400, and did not have to buy the expensive Canon.

The 7D will try to AF when using Live view and contrast detect AF. It's not fast, but it works with f/8. Until you get a 7D Mark II or 1DX or...

BigAl007 wrote in post #17477113
Looks like Canon service have made a mistake. The original 7D did not have f/8 center spot focus capacity. The first camera other than a 1 series to have the f/8 feature was the 5D Mark III followed by the 7D Mark II. They are currently the only two non 1 series cameras to feature f/8 center point focus.

Alan

Well, technically, it'd AF at 100mm (140mm), right? Yes, that is, of course, not the point.

oingyboingybob wrote in post #17477450
Canon's responses were confusing, to say the least. I did send another email to them following their first reply where they informed me the combination of that lens and 1.4x extender would work. The 2nd response told me exactly the opposite. I'm not particularly disappointed as to put an extender on this, or any other high-quality lens, is not something I would normally do or recommend as results can be mixed to say the least but it would have been nice to have the facility of AF and longer reach for the odd occasion where approach to a distant subject is restricted. There's always MF as a fallback though - but not as convenient when subjects are moving. I am considering the 7D Mk2 but I'm not yet convinced that it's worth the expense, particularly as a pro photographer friend of mine is currently having focus problems with hers. She's having a dialogue with Canon (Australia) so I hope that the responses she gets are a bit more consistent that I had from Canon UK.

Lots of examples of 100-400 II with 1.4 TC posted on POTN. I have also been using Canon 1.4TC II with 100-400 II and I'm very satisfied with results.

See bottom of this page for x_tan's results with 3.4 TC (1.4 and 2 stacked !)
https://photography-on-the.net …ead.php?t=14116​27&page=20

One of those examples:
[IMAGE'S LINK: https://flic.kr/p/rtXD​6s]Lunch @ 1120mm by x_tan, on Flickr

Here's one of mine, 100-400II with EF 1.4TC II.
Full pic and a crop: