# Kenko TC and AF at F8



## Mt Spokane Photography (Oct 6, 2012)

After reading that the 1.4X Kenko PRO 300 DGX was autofocusing at f/8 with Canon super teles on 1D X Bodies, as well as reading the experiences of some who posted here with the 5D Mark III, I decided to go for it.
My TC arrived late this afternoon, and I decided to give it a try on my 100-400mmL. At 100mm, its a equivalent of f/6.3, and the 5D MK III indicates f/6.3.
I tried it indoors in fair-good light, and it autofocused smoothly and quickly. Then I zoomed out to 400mm which is f/8 equivalent, and I was pleased when it snapped into focus repeatedly.
Then, I decided to give it a tough test, and took it outdoors where it was rapidly becoming dark. This is the area where TC's usually fall flat. I zoomed out to 400mm on a far distant house with the sky still a little bid bright, and it did a fair job of autofocusing. slower, but suprisingly fast for the situation. The ISO level was 8000, but the image under exposed.
Then, I tried it without the sky in the background on my rose bush in deep shadows, but it would just hunt. This was a very dark area. Finally, I tried it on my bird feeder at ISO 12800, which was a correct exposure, and it smapped to focus quickly. I was amazed.
Its too late to do any more testing tonight, but I'll try testing other lenses and combinations as I can make time.
Already, I can say its worth the price over a Canon 1.4X MK II TC as long as you do not need weather sealing.


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## WesternGuy (Oct 11, 2012)

Do you have any more test results to report? If this unit will focus when it is on the the new 600mm f4L IS II, then it is probably worth the extra $$. Just curious, that's all.

WesternGuy


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## K-amps (Oct 11, 2012)

Also can you compare sharpness to the Canon 1.4 mk.iii please.


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## neuroanatomist (Oct 11, 2012)

WesternGuy said:


> If this unit will focus when it is on the the new 600mm f4L IS II, then it is probably worth the extra $$.



???

Certainly it will AF. So will the Canon 1.4xIII, since either 1.4x TC will make an f/4 lens into an f/5.6 lens, and all Canon bodies can AF with an f/5.6 lens. 

Did you mean will the Kenko 2x allow AF with the resulting f/8 combo. A poster on a bird forum reported that it will, but also showed that unlike the Kenko 1.4x which has decent IQ, their 2x turns a sharp lens to mush.


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## Mt Spokane Photography (Oct 11, 2012)

neuroanatomist said:


> WesternGuy said:
> 
> 
> > If this unit will focus when it is on the the new 600mm f4L IS II, then it is probably worth the extra $$.
> ...


+1.
Thanks Neuro. hand surgery tody, so I can't type well much less test cameras. It did work very well on my old 10D - suprising. I do not have many f/5.6 lenses to test it with.


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## neuroanatomist (Oct 11, 2012)

Hope the surgery went well!

Regarding the Kenko 1.4x, maybe I blew it. I could have just gotten that to use with my 100-400 for a 560mm f/8 lens with AF. Let's say the Kenko is as good optically as the 1.4xII - that can't be too bad compared to the 600mm f/4L IS II, can it?!?

Actually, on a serious note, Art Morris is really pleased about the Kenko 1.4x and the 800/5.6L IS. He's got some very nice image to back that up. But interestingly, when I look at TDP's ISO 12233 crops, the optical performance of the 800/5.6 + 1.4x (no real difference between MkII vs. MkIII there) and the 600/4 II + 2x (link), they look pretty similar (which makes sense - the 600 II is a better lens, and the 600 II + 1.4x is optically a tiny bit better than the 800/5.6). So, for static subjects (where Live View AF would work fine), the 600 II plus Canon 2x would be worth a try...

Now I just need to decide if it's worth swapping the 2xII that I have for a 2xIII. There is a chart comparison for the 2xII vs. 2xIII with the 70-200 II, and there's a marginal improvement - since I'll occasionally use that combo (when I don't want to bring both the 70-200 II and the 100-400), it may be worth upgrading just for that...


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## Mt Spokane Photography (Oct 11, 2012)

neuroanatomist said:


> Hope the surgery went well!
> 
> Regarding the Kenko 1.4x, maybe I blew it. I could have just gotten that to use with my 100-400 for a 560mm f/8 lens with AF. Let's say the Kenko is as good optically as the 1.4xII - that can't be too bad compared to the 600mm f/4L IS II, can it?!?
> 
> ...


I took some pain killer, so it feels better now. The surgery went fine, my left hand was done 3 weeks ago and is healing well. I want to be healed before winter, I'm out in the country and have to run my tractor to plow my almost 1/4 mile driveway. I need a good grip sometimes when it starts sliding.
I'll also want to try the TC on my 100L, more magnification is sometimes handy, I don't have the mp-e 65. I did put it on my 24-105 where it worked fine, but there is little point to using it there.
I do have a number of older consumer grade lenses which are marginal without a TC, but I might try it with them just to see if they autofocus.
I'm also curious about combinations of TC's, With my 1D MK III I've seen my 1.4X and 2X autofocus even at f/11.


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## AlanF (Oct 11, 2012)

I tested the Kenko 1.4x last week on my 7D and 100-400mm L, and it worked fine. The focus was quick and the IQ better than the without scaled by 1.4 in Photoshop. But, it wouldn't autofocus when stacked on my favourite hand-held 600 mm combo of a Canon 2xtc III with a 300mm f/2.8 II. The 2xtc slows down the 300 focussing by a factor of 4 and the extra 1.4 Tc is too much. The reproducibility of focus of the Mk II 300mm is far better than that of the 100-400mm so perhaps the sloppier focussing of the older lens is more tolerant to f/8.


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## AudioGlenn (Oct 11, 2012)

Mt Spokane Photography said:


> neuroanatomist said:
> 
> 
> > WesternGuy said:
> ...



re: hand surgery. get well soon


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## WesternGuy (Oct 11, 2012)

Okay guys, I am a bit new to this forum and it seems like I need a little help here. I just tried my Canon 1.4x III on my 100-400 and I could not get it it AF at 100mm or at 400mm on my 1D X. Am I doing something wrong? If so, can anyone give me any suggestions as to how to make this happen? Thanks.

WesternGuy


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## neuroanatomist (Oct 11, 2012)

WesternGuy said:


> I just tried my Canon 1.4x III on my 100-400 and I could not get it it AF at 100mm or at 400mm on my 1D X. Am I doing something wrong? If so, can anyone give me any suggestions as to how to make this happen?



What you're doing 'wrong' is using the Canon 1.4x. The 100-400mm is an f/4.5-5.6 lens, so putting on a 1.4x TC makes it an f/6.3-8 lens. The 1D X requires a max aperture of f/5.6 for AF to work (note that previous 1-series bodies could AF with an f/8 combo, although only with the center AF point). 

Unlike the Canon TCs, the electronics Kenko 1.4x and 2x TCs somehow 'spoof' the camera into not seeing the TC for AF purposes (the aperture reported in EXIF _does_ reflect the TC being there). Side note, the 1D X also does not see the TC for metering, so you need to apply one stop of EC with the Kenko 1.4x and 2 stops with the Kenko 2x, other bodies, e.g. 5DIII, 7D, don't seem to have the metering effect, but still AF fine).

The reason (some) people are up in arms over this is that it pretty clearly shows that the 1D X (and other bodies) _can_ AF at f/8, but Canon is locking that function out in firmware.


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## K-amps (Oct 11, 2012)

Looks like someone in Canon is under huge (short term) pressure to boost profitability... the new buzzword (again) is selling high margin products... f5.6 lenses probably have better margins than f8. I can understand why the customers are feeling like their interests did not matter.


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## K-amps (Oct 11, 2012)

Mt Spokane Photography said:


> hand surgery tody, so I can't type well much less test cameras. It did work very well on my old 10D - suprising. I do not have many f/5.6 lenses to test it with.



Hope the recovery goes well.


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## WesternGuy (Oct 11, 2012)

neuroanatomist said:


> WesternGuy said:
> 
> 
> > I just tried my Canon 1.4x III on my 100-400 and I could not get it it AF at 100mm or at 400mm on my 1D X. Am I doing something wrong? If so, can anyone give me any suggestions as to how to make this happen?
> ...


neuroanatomist, thank you for the explanation. Hopefully, someone in the Canon organization will wake up and see what the competition is doing and upgrade the firmware. Guess I need to put a Kenko 1.4x in my next order.

WesternGuy


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## lorenbc (Oct 11, 2012)

AlanF said:


> I tested the Kenko 1.4x last week on my 7D and 100-400mm L, and it worked fine. The focus was quick and the IQ better than the without scaled by 1.4 in Photoshop. But, it wouldn't autofocus when stacked on my favourite hand-held 600 mm combo of a Canon 2xtc III with a 300mm f/2.8 II. The 2xtc slows down the 300 focussing by a factor of 4 and the extra 1.4 Tc is too much. The reproducibility of focus of the Mk II 300mm is far better than that of the 100-400mm so perhaps the sloppier focussing of the older lens is more tolerant to f/8.



Alan -

Were you able to use all AF points? I've only been able to use the outer left and right points (4 on each side) with that same combination; I'd love to get it working with all, or at least, most, points.


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## AlanF (Oct 11, 2012)

Loren
I do bird photography and use spot autofocus with the centre spot. I have read that the outer zones are more sensitive but the centre focused well. 
Alan


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## Mt Spokane Photography (Oct 11, 2012)

WesternGuy said:


> neuroanatomist, thank you for the explanation. Hopefully, someone in the Canon organization will wake up and see what the competition is doing and upgrade the firmware. Guess I need to put a Kenko 1.4x in my next order.
> 
> WesternGuy


I'm afraid that Canon's version of Upgrade the firmware is to upgrade it so the Kenko will not work.


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## K-amps (Oct 12, 2012)

Mt Spokane Photography said:


> WesternGuy said:
> 
> 
> > neuroanatomist, thank you for the explanation. Hopefully, someone in the Canon organization will wake up and see what the competition is doing and upgrade the firmware. Guess I need to put a Kenko 1.4x in my next order.
> ...



+1


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## Chris_prophotographic (Oct 12, 2012)

So with the 2x Kenko TC attached to the 1DX is AF slow and useless or sluggish or just a peppy as it should be?

anyone having a go with this right now??


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## WesternGuy (Oct 12, 2012)

Mt Spokane Photography said:


> WesternGuy said:
> 
> 
> > neuroanatomist, thank you for the explanation. Hopefully, someone in the Canon organization will wake up and see what the competition is doing and upgrade the firmware. Guess I need to put a Kenko 1.4x in my next order.
> ...


I am afraid that you might be right, but let's hope they don't find out - :-X - ya, like that's going to happen - :

WesternGuy


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## Mt Spokane Photography (Oct 12, 2012)

Chris_prophotographic said:


> So with the 2x Kenko TC attached to the 1DX is AF slow and useless or sluggish or just a peppy as it should be?
> 
> anyone having a go with this right now??


Avoid the Kenko 2X, it is weak. The 1.4X is good though.


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## lorenbc (Oct 14, 2012)

AlanF said:


> Loren
> I do bird photography and use spot autofocus with the centre spot. I have read that the outer zones are more sensitive but the centre focused well.
> Alan



I'll try spot; the regular center point just hunts with the 100-400+1.4.

Thanks.

Loren


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## Mt Spokane Photography (Oct 14, 2012)

lorenbc said:


> AlanF said:
> 
> 
> > Loren
> ...


Be sure its the Pro 300 DGX version. There are some who say that only recent production of these will AF at f/8.
I did use the center poing, but not spot. My Canon 10D doesn't even have spot, but it worked very well as did my 5D MK III.


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## lorenbc (Oct 14, 2012)

Mt Spokane Photography said:


> lorenbc said:
> 
> 
> > AlanF said:
> ...



Yep...it's definitely PRO DGX with the green (or was it blue) dot on the box (I don't have the box handy). Actually. just remembered my wife has one, too, so I'll try hers, too, and see if it's any different.

Loren


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## Lnguyen1203 (Oct 15, 2012)

After reading Authur Morris blog, I went for the Kenko 1.4 Teleplus for use with my 70-300L f4-5.6 and Canon 5D3. I'm happy to report that the 5D3 retains all 61 points AF. The AF at F8 isn't bad at all and the IQ is useable. I have also a 300F2.8 + 1.4X and 2X, but for a walk around lens, the 70-300L is much lighter and the Kenko 1.4X does a pretty good job. Will test some more in the weeks to come. The attached photos are shot at 1/2500, f8, ISO 1250, 420mm. The focus is spot on as in the second photo.


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## Mt Spokane Photography (Oct 16, 2012)

lorenbc said:


> Yep...it's definitely PRO DGX with the green (or was it blue) dot on the box (I don't have the box handy). Actually. just remembered my wife has one, too, so I'll try hers, too, and see if it's any different.
> 
> Loren


I checked my box, its still laying here. It has a blue dot. That usually means some sort of rework or upgrade has been incorporated.
I do set the 100-400Lfocus distance limiter to the 6.5m - infinity setting and then the lens does not run thru its entire AF range. That makes a huge difference in time to find focus.


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## lorenbc (Oct 17, 2012)

Mt Spokane Photography said:


> lorenbc said:
> 
> 
> > Yep...it's definitely PRO DGX with the green (or was it blue) dot on the box (I don't have the box handy). Actually. just remembered my wife has one, too, so I'll try hers, too, and see if it's any different.
> ...



I found something interesting today; I grabbed my wife's copy of the 1.4 DGX Pro and noticed that hers has a blue dot...mine has a green dot...and when I tested it with the 7D+100-400, the center point worked! So, it would seem that the blue dot version has some enhancement above and beyond the green dot version. So, needless to say, I replaced the green dotted copy in my wife's bag and went on my merry way <grin>. She never uses it anyway!


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## Mt Spokane Photography (Oct 17, 2012)

I never did get to test mine, I have been recovering from hand surgery, and thought maybe I could try it with my 100mm L this morning. The TC was totally dead, and froze up the camera. After trying it with my 100-400mmL and on my 10D with the same results, I made sure there were no problems with the contacts, and then packed it up to go back for a refund. I do not want another from the same lot.
Now, I'll probably just wait and see if Canon upgrades the 5D MK III. if not, I'll get another Kenko.


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## WesternGuy (Oct 18, 2012)

Well, I guess this all changes for 1D X owners with the issue of the upgrade 1.1.1. I have made the upgrade and now all I have to do is test it out and see what happens.

WesternGuy


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## neuroanatomist (Oct 19, 2012)

WesternGuy said:


> Well, I guess this all changes for 1D X owners with the issue of the upgrade 1.1.1. I have made the upgrade and now all I have to do is test it out and see what happens.



Worked decently today with the 600 II and 2xIII. There was some focus hunting when shooting birds in dense foliage with backlighting, and I thought, hmmmm, is this because of the 2x? So I switched to the 1.4xIII, and the hunting was no different. It was a bit better with the bare lens, but still not perfect. When I moved to a different angle that eliminated the backlighting, it was fine.


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## Mt Spokane Photography (Oct 19, 2012)

I think that the system was not intended to do well at f/8, but they decided that it was good enough for most usage. Certainly, my 5D MK III did very well with the Kenko 1.4X and 100-400 while at 400mm. At least until the Kenko died. Everything is working fine since I removed the TC.


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## neuroanatomist (Oct 19, 2012)

neuroanatomist said:


> There was some focus hunting when shooting birds in dense foliage with backlighting



Here's a shot that shows the bird and surround, a tough job for any AF system. This was with phase AF, and I haven't done an AFMA yet (need to find a deserted football field for that!). Might be a little back-focused, I think.

Shot is with the 1D X and 600mm f/4L IS II + 2xIII, 1/320 s, f/8, ISO 4000. Original and a 100% crop to show detail, which is quite good, IMO.


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## Mt Spokane Photography (Oct 19, 2012)

Wow, the backlighting is tough to deal with. It might be a hair backfocused. 
I had the older non is 600mm f/4. It was too much for me to haul around and setup, but it did a great job. I finally resigned myself to making do with my 100-400mmL, and its pretty good.


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## WesternGuy (Oct 19, 2012)

Neuro, wow - that looks great - I can hardly wait to get my 600mm II.

WesternGuy


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