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Occasional Contributor
Posts: 5
Registered: ‎04-21-2018

Re: Canon EF 100-400 f/4-5.6L with 2x extender

I must be doing something wrong. I have “live view” enabled in my EOS 70D and the switch on the back of the camera is set to live view. I am using a 2x ii extender. Autofocus will not work. When I try to focus on an object, the f stop setting is flashing on the display. Any suggestions?

Honored Contributor
Posts: 6,574
Registered: ‎08-13-2015

Re: Canon EF 100-400 f/4-5.6L with 2x extender


@GeorgeMwrote:

I must be doing something wrong. I have “live view” enabled in my EOS 70D and the switch on the back of the camera is set to live view. I am using a 2x ii extender. Autofocus will not work. When I try to focus on an object, the f stop setting is flashing on the display. Any suggestions?


What shooting mode are you using.  Try using M mode.  How many focus points are you using?  Use just the center one in the viewfinder, and then try Live View, although I do not think that will really help.

 

The minimum aperture is probably too high.  With the adapter, you will get a minimum range of f/8-11.  You say the f/stop is flashing.  What value of f/stop is it displaying as it flashes?

 

The EF 2x models are not recommended for use with lenses with minimum apertures exceeding f/4.  The extender instruction manual can tell you which combinations of lenses it is compatible with.  You camera instruction manual should tell you which focus points would be available, which in this case I would expect none to be available in the viewfinder.

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"I don't rent software. I use Photoshop CS6, ACR 9.8 and Lightroom 6.8 ."
Occasional Contributor
Posts: 5
Registered: ‎04-21-2018

Re: Canon EF 100-400 f/4-5.6L with 2x extender

I followed your instructions and finally managed to get it to work. I have to manually tweak the focus on the object. After that the autofocus seems to take over. It works that way in both the M and the Av modes. F-stop has to be set at 6 or above. Focusing is a slow process so it’s probably not good for bird photography.

Honored Contributor
Posts: 6,574
Registered: ‎08-13-2015

Re: Canon EF 100-400 f/4-5.6L with 2x extender


@GeorgeMwrote:

I followed your instructions and finally managed to get it to work. I have to manually tweak the focus on the object. After that the autofocus seems to take over. It works that way in both the M and the Av modes. F-stop has to be set at 6 or above. Focusing is a slow process so it’s probably not good for bird photography.


Well, that is good news.  You are able to get it to focus, but you are running up against the limitations of the 2x extender.

 

Be aware that the camera uses one AF system for when you use the viewfinder, and another AF system when you use Live View mode.  As a general rule, most of the auto focus specifications that describe a camera are describing shooting through the viewfinder, not Live View mode.

 

The viewfinder focusing system is much faster than the Live View mode auto focusing system.  The 2x extender will only slow down the performance of either focusing system.  Slower focusing is the price you pay for extended focal length.  You should see an improvement in Live View focusing speed without the 2x extender, but it will never compare to the performance of the viewfinder AF system.

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"I don't rent software. I use Photoshop CS6, ACR 9.8 and Lightroom 6.8 ."
Occasional Contributor
Posts: 5
Registered: ‎04-21-2018

Re: Canon EF 100-400 f/4-5.6L with 2x extender

I used the extender yesterday, in the field, while photographing birds. I was able to bump up the shutter speed to get decent results. But, for most of the photos, I had to rely on manual focus. End result...about a third were out of focus. About half that were focused were great!

 

Thank you for the input.

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Esteemed Contributor
Posts: 4,536
Registered: ‎06-25-2014

Re: Canon EF 100-400 f/4-5.6L with 2x extender


@GeorgeMwrote:

I used the extender yesterday, in the field, while photographing birds. I was able to bump up the shutter speed to get decent results. But, for most of the photos, I had to rely on manual focus. End result...about a third were out of focus. About half that were focused were great!

 

Thank you for the input.


When you live on the edge, you're going to get corresponding results. But let's face it: In the digital world, where it costs you nothing to shoot all you want, a one in three keeper rate ain't bad.

Bob
Boston, Massachusetts USA
Occasional Contributor
Posts: 5
Registered: ‎04-21-2018

Re: Canon EF 100-400 f/4-5.6L with 2x extender

Absolutely!

Esteemed Contributor
Posts: 3,614
Registered: ‎06-11-2013

Re: Canon EF 100-400 f/4-5.6L with 2x extender


@RobertTheFatwrote:

@GeorgeMwrote:

I used the extender yesterday, in the field, while photographing birds. I was able to bump up the shutter speed to get decent results. But, for most of the photos, I had to rely on manual focus. End result...about a third were out of focus. About half that were focused were great!

 

Thank you for the input.


When you live on the edge, you're going to get corresponding results. But let's face it: In the digital world, where it costs you nothing to shoot all you want, a one in three keeper rate ain't bad.




Especially when you compare that to the price of the lens that provides the focal length with a lower focal ratio.  

 

You could certainly buy the Canon EF 800mm f/5.6L... for the low bargain price of merely (as I quickly Google the price on B&H Photo) ... OOOH... just $12,999.00 (buy two so you have a backup!)

 

So yeah... I think I’d go with the 1 in 3 keeper rate and save $10k in the process (unless someone else is footing the bill and your career is on the line.)

 

 

Tim Campbell
5D III, 5D IV, 60Da
Honored Contributor
Posts: 6,574
Registered: ‎08-13-2015

Re: Canon EF 100-400 f/4-5.6L with 2x extender


@GeorgeMwrote:

I used the extender yesterday, in the field, while photographing birds. I was able to bump up the shutter speed to get decent results. But, for most of the photos, I had to rely on manual focus. End result...about a third were out of focus. About half that were focused were great!

 

Thank you for the input.



 When manual focusing, it helps me to be very familiar with the available depth of field, and what is the hyperfocal distance of my lenses at given aperture settings.

 

http://www.dofmaster.com/doftable.html

 

I review this chart frequently, to help with selecting lenses.

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"I don't rent software. I use Photoshop CS6, ACR 9.8 and Lightroom 6.8 ."
Occasional Contributor
Posts: 5
Registered: ‎04-21-2018

Re: Canon EF 100-400 f/4-5.6L with 2x extender

Which is wh6 I have the lens that I have. I also have a 4oo FFL Lens that has a similar f stop rating.  Can’t afford the better one.

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