topic 1.4x Extender iii function in EOS DSLR & Mirrorless Cameras

1.4x Extender iii function

Birdeye — Sat, 03 Mar 2018 01:11:17 GMT

I purchased the 1.4x Extender iii to use with a Canon 70D and the Canon EF 100-400mm f/4.5-5.6L IS II USM lens. I am not able to find setting for which the AF will work when looking through the viewfinder. The AF will work in live view. My question is will these three components ever allow AF without live view? A second question is will AF work with these components if a 7D II camera body is used instead of the 70D?

Re: 1.4x Extender iii function

MikeSowsun — Sat, 03 Mar 2018 01:46:39 GMT

Like most consumer grade DSLR's, your 70D needs a minimum of f/5.6 for phase-detection Auto Focus. That is why the 100-400 1.4x combo won't work for you. You will need to uograde to a 5D Mark III, 7D Mark II, or 80D in order to AF at f/8

Re: 1.4x Extender iii function

Waddizzle — Sat, 03 Mar 2018 01:57:11 GMT

@Birdeyewrote:
I purchased the 1.4x Extender iii to use with a Canon 70D and the Canon EF 100-400mm f/4.5-5.6L IS II USM lens. I am not able to find setting for which the AF will work when looking through the viewfinder. The AF will work in live view. My question is will these three components ever allow AF without live view? A second question is will AF work with these components if a 7D II camera body is used instead of the 70D?

When you use an extender, you get the benefit of apparent extended focal length. Since nothing in life is free, the price you pay is that the minimum aperture range of the lens being used gets raised by one full stop. Your f/4.5-5.6 lens becomes a f/6.3-8 lens.

A check of the specs show that the 70D does not have AF points sensitive enough to focus at a minimum aperture smaller than f/5.6. Remember, a lens focuses at its’ widest aperture, and then stops down to take a photograph. When using the adapter, the widest aperture is at 100mm, and the value would be f/6.3. At 400mm, the widest aperture would be f/8. These aperture values are too narrow for your 70D to auto focus.

Some of the high models have a center AF point that is sensitive at f/8. The 7D2 is one of those camera bodies with a center AF point that is sensitive at f/8. This means when the EF 100-400mm f/4.5-5.6L IS II USM + EF1.4x III is used with the 7D2, you will see only one available AF point, although the 7D2 will allow the surrounding AF points to act as focus assist points, effectively expanding the AF coverage of th single AF point.

For the record, it is my understanding that the lens/extender combo will allow a row of 9 AF active AF points on the 1Dx Mark II. For comparison, the 80D will allow three rows of 9 AF points, as will the 6D2 and the 77D.

Re: 1.4x Extender iii function

Birdeye — Sat, 03 Mar 2018 02:35:09 GMT

Thank you MikeSowsun and Waddizzle! Your explanations are clear and very helpful I am certain others will benefit as well from your responses. By the way, your information is much more to the point and understandable than what I received from Canon tech support. I am veryhappy I posted my query here.

Re: 1.4x Extender iii function

diverhank — Sat, 03 Mar 2018 02:46:44 GMT

@Birdeyewrote:
Thank you MikeSowsun and Waddizzle! Your explanations are clear and very helpful I am certain others will benefit as well from your responses. By the way, your information is much more to the point and understandable than what I received from Canon tech support. I am veryhappy I posted my query here.

Of course if you want this to work (albeit sluggishly), you can tape some of the pins on the 1.4X. You can google how to do it easy enough.

Re: 1.4x Extender iii function

Birdeye — Sat, 03 Mar 2018 03:28:31 GMT

Thanks diverhank! I've read about this online and have wondered if equipment could be damaged that way. Also, setting the lens to manual works better than live view -- I photo birds and the eye must be in focus or you really don't have a picture (hence my user name). Yet birds don't always wait for manual focus (hence my dilemma).

Re: 1.4x Extender iii function

diverhank — Sat, 03 Mar 2018 08:55:16 GMT

@Birdeyewrote:
Thanks diverhank! I've read about this online and have wondered if equipment could be damaged that way. Also, setting the lens to manual works better than live view -- I photo birds and the eye must be in focus or you really don't have a picture (hence my user name). Yet birds don't always wait for manual focus (hence my dilemma).

No there should be no damage, at least it never damages my camera/lens. By taping the pin, the lens can't report the aperture to the camera and it continues to focus...the camera is programmed to stop focus, not that it can't. I used to do this all the time when I had the 50D that can't focus at f/8.

By the way, I believe that live view focus still works for f/8. For non-moving birds, that should work really well.

Re: 1.4x Extender iii function

ebiggs1 — Sat, 03 Mar 2018 18:08:45 GMT

"Yet birds don't always wait for manual focus (hence my dilemma)."

And, at one time we didn't have AF on any lens or camera. Guess what? We got the photos anyway. It can be done!

Re: 1.4x Extender iii function

ebiggs1 — Sat, 03 Mar 2018 18:11:56 GMT

"...much more to the point and understandable than what I received from Canon tech support"

I am curious? What did Canon tell you? They usually are pretty good and through. If you happen to get a bad one just hang up and call right back They have some great people.

Re: 1.4x Extender iii function

Birdeye — Sat, 03 Mar 2018 22:34:23 GMT

ebiggs1: Yes, indeed. I began with a Canon AE1 in 1978 however none of my bird photos from the film days compare with what digital today can do. I find on the bird websites some incredible shots from average photographers. Most people who take bird photos today are birders who carry a camera, or "guy with camera" in he vernacular of some photographers, yet they get really good photos. And, with digital we can take far more photos today that we could with expensive film thus increasing the probability of an accidental good capture. Back in the time you are talking about most of the good photos were taken by photographers, like Eliot Porter, or ornithologists who spent a lot of time with cameras (e.g. Arthur A. Allen, Chester A. Reed, William Lovell Finley, and R. W. Shufeldt) rather birders with cameras. More recently, 1990s, Bill Burt has taken some outstanding photos of birds on film.

Re: 1.4x Extender iii function

Birdeye — Sat, 03 Mar 2018 22:43:13 GMT

ebiggs1: Yes, I have called Canon tech support before and have been satisfied with the answers. This time around however I got a guy who did not leave me with a lot of confidence in the correctness of what he said. His answers did not explain things in the technical terms of the two good responses, Mike Sowsun and Waddizzle, I received here. He tried so I don't wish to bash him.

Re: 1.4x Extender iii function

RobertTheFat — Sun, 04 Mar 2018 00:44:50 GMT

@ebiggs1wrote:
"Yet birds don't always wait for manual focus (hence my dilemma)."

And, at one time we didn't have AF on any lens or camera. Guess what? We got the photos anyway. It can be done!

Yeah, but cameras in those days had manual focusing aids that most current cameras lack. My Nikon F-2 had a split-image rangefinder and a Fresnel ring built into the viewfinder. None of my digital cameras have had anything comparable.

Re: 1.4x Extender iii function

Birdeye — Sun, 04 Mar 2018 02:25:07 GMT

Good point! I had forgotten about the split image. We got by not know anything about the coming technology. I wonder what is around the corner that we can not now concieve. Will we be saying some day that all we had was a hunting AF?

I hope, RobertTheFat, that you are weathering the bomb cyclone.

Birdeye

Bozeman, MT

Re: 1.4x Extender iii function

RobertTheFat — Sun, 04 Mar 2018 14:43:37 GMT

@Birdeyewrote:
Good point! I had forgotten about the split image. We got by not know anything about the coming technology. I wonder what is around the corner that we can not now concieve. Will we be saying some day that all we had was a hunting AF?

I hope, RobertTheFat, that you are weathering the bomb cyclone.

Birdeye
Bozeman, MT

Thanks for the thought, Birdeye. We're about 20 miles inland, so all we got was rain and occasional howling winds. It was the towns along the shore that got inundated.

Re: 1.4x Extender iii function

ebiggs1 — Sun, 04 Mar 2018 15:23:31 GMT

"Yeah, but cameras in those days had manual focusing aids that most current cameras lack."

Yeah, there Robert, I wonder why Canon even bothers to put a AF/MF switch on their lenses. We are such complete boobs that we can't use it. A poor workman always blames his tools

Re: 1.4x Extender iii function

RobertTheFat — Sun, 04 Mar 2018 18:29:34 GMT

@ebiggs1wrote:
"Yeah, but cameras in those days had manual focusing aids that most current cameras lack."

Yeah, there Robert, I wonder why Canon even bothers to put a AF/MF switch on their lenses. We are such complete boobs that we can't use it. A poor workman always blames his tools

Sorry, Ernie, I wasn't trying to be argumentative or blame my tools. It didn't occur to me that you wouldn't have gotten the more elaborate focusing screen for your Nikons. If it had, I wouldn't have brought it up.

Re: 1.4x Extender iii function

PLee — Sun, 04 Mar 2018 19:44:01 GMT

@Waddizzlewrote:
@Birdeyewrote:
I purchased the 1.4x Extender iii to use with a Canon 70D and the Canon EF 100-400mm f/4.5-5.6L IS II USM lens. I am not able to find setting for which the AF will work when looking through the viewfinder. The AF will work in live view. My question is will these three components ever allow AF without live view? A second question is will AF work with these components if a 7D II camera body is used instead of the 70D?
When you use an extender, you get the benefit of apparent extended focal length. Since nothing in life is free, the price you pay is that the minimum aperture range of the lens being used gets raised by one full stop. Your f/4.5-5.6 lens becomes a f/6.3-8 lens.

A check of the specs show that the 70D does not have AF points sensitive enough to focus at a minimum aperture smaller than f/5.6. Remember, a lens focuses at its’ widest aperture, and then stops down to take a photograph. When using the adapter, the widest aperture is at 100mm, and the value would be f/6.3. At 400mm, the widest aperture would be f/8. These aperture values are too narrow for your 70D to auto focus.

Some of the high models have a center AF point that is sensitive at f/8. The 7D2 is one of those camera bodies with a center AF point that is sensitive at f/8. This means when the EF 100-400mm f/4.5-5.6L IS II USM + EF1.4x III is used with the 7D2, you will see only one available AF point, although the 7D2 will allow the surrounding AF points to act as focus assist points, effectively expanding the AF coverage of th single AF point.

For the record, it is my understanding that the lens/extender combo will allow a row of 9 AF active AF points on the 1Dx Mark II. For comparison, the 80D will allow three rows of 9 AF points, as will the 6D2 and the 77D.

The bolded comment is not correct and I wanted to clarify. Both the EOS-1D X Mark II and EOS 5D Mark IV support full time AI Servo AF with all 61 AF points when using the EF 100-400mm f/4.5-5.6L IS II USM with the Extender EF 1.4x III. Note that this functionality is not necessarily maintained especially with older long glass combined with older version extenders. In the OP's lens and extender scenario, the EOS 6D Mark II, EOS 80D and EOS 77D will support 27 points for AF out of their 45 point arrays at f/8. Access to a larger array of points in AI Servo can clearly have significant advantages for focusing on difficult to track subject matter and modern Canon EOS DSLRs offer a lot of that functionality.

Re: 1.4x Extender iii function

Waddizzle — Mon, 05 Mar 2018 00:20:53 GMT

“For the record, it is my understanding that the lens/extender combo will allow a row of 9 AF active AF points on the 1Dx Mark II. For comparison, the 80D will allow three rows of 9 AF points, as will the 6D2 and the 77D.

The bolded comment is not correct and I wanted to clarify. Both the EOS-1D X Mark II and EOS 5D Mark IV support full time AI Servo AF with all 61 AF points when using the EF 100-400mm f/4.5-5.6L IS II USM with the Extender EF 1.4x III. Note that this functionality is not necessarily maintained especially with older long glass combined with older version extenders. In the OP's lens and extender scenario, the EOS 6D Mark II, EOS 80D and EOS 77D will support 27 points for AF out of their 45 point arrays at f/8. Access to a larger array of points in AI Servo can clearly have significant advantages for focusing on difficult to track subject matter and modern Canon EOS DSLRs offer a lot of that functionality.”

Actually, I do not own a 1Dx Mark II, and what you described was my assumption, that all AF points should be active. But, I was corrected, and told differently, that only a single row of 9 AF points will be active with this particular lens/extender combo.