April 25, 2014, 01:58:56 AM

Author Topic: Canon EOS-1D X AF at f/8 with the Kenko 1.4TC  (Read 11735 times)

TexPhoto

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Re: Canon EOS-1D X AF at f/8 with the Kenko 1.4TC
« Reply #15 on: September 04, 2012, 08:23:42 PM »
OK, to understand why this works, you need to understand the camera refuses to AF with the Canon extender because it's being told there is an f8 (or f11 for the 2X) lens on the front.  The software of the camera then declares "hell no".

The Kenko converter is passing the f stop of the lens without the change in aperture.  So the camera thinks there is an f5.6 lens on it.  Now you still need decent light and a contrasty subject, more than without the telecenter, but it still works.

Why the -1?  Because he camera is metering at f8 while being told it has f5.6.  So before the photo is taken, it is metering wrong.

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Re: Canon EOS-1D X AF at f/8 with the Kenko 1.4TC
« Reply #15 on: September 04, 2012, 08:23:42 PM »

Portrait_Moments_Photogra

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Re: Canon EOS-1D X AF at f/8 with the Kenko 1.4TC
« Reply #16 on: September 04, 2012, 09:58:30 PM »
5.6 plus 2x = f/11 - there's no camera that AF at f/11.... :(

you can manual focus though on bright daylight

My 1D Mark IIN and your 1D Mark IV will work on f/8 but not f/11 - none does :)

hope this helps your inquiry.

Thanks. I only ask since I saw this quote in the thread Birdsasart.com:

"I did not test the Kenko Pro since Artie had already confirmed that the Pro DGX did not work with 5DIII. The Kenko 1.4X MC4 would cause the same error as the Pro DGX with the 5DIII/800 combo. However, the 2X would work and would even autofocus at f11 with the 5DIII. "

Hhhmmmmm, HOLY COW Rick!!!!! my 1D Mark IIN with 400L 5.6 plus 2x Kenko f/11 - DOES AF and LOCKS!!!!
and I'm inside the house - night time - on daytime - bright sunlight - THIS WILL ROCK!!!

What a shame for Canon.... :(

Portrait_Moments_Photogra

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Re: Canon EOS-1D X AF at f/8 with the Kenko 1.4TC
« Reply #17 on: September 04, 2012, 10:08:29 PM »
now with my 1DX, im starting to feel really cheated by Canon - i really do.

my 7 year old 1D Mark IIN and 8 yr old 1D Mark II paired with a third party TC works at f/11 just fine
~ while my 1DX wont.

also - tested it on the Canon T3 - it worked - a bit slower than the 1D Mark II's but very acceptable.

      - tested on the 5D Mark II - it will AF and Lock only if you pre-focus it manually.
      - 5D Mark II without pre-focus will AF and Lock 1 out of 10 or even more - so not acceptable in any standard.

but they will work - while the 1DX wont - WTH Canon!!!!

stochasticmotions

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Re: Canon EOS-1D X AF at f/8 with the Kenko 1.4TC
« Reply #18 on: September 04, 2012, 10:09:06 PM »
I have been using the kenko 1.4 DGX for quite some time with my 5d Mark II and the 100-400.  At 400 it focuses quite quickly except in the lowest of light (using the centre focus point mostly).  It also metres correctly and shows f8 both on the camera and in the exif.  With the Canon 1.4 I had to tape up some of the connectors and then although it would focus it was very slow and would not correctly show the aperture.

As a side note the kenko is much sharper that the canon (I have the version 2 of the 1.4 canon teleconverter) at least at f8-f11.  I have tried it on an old 500 f4.5 and it also worked like a charm.  These teleconverters do not focus quickly with my 7D (or at all but in the brightest light)


Rick Massie

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Re: Canon EOS-1D X AF at f/8 with the Kenko 1.4TC
« Reply #19 on: September 04, 2012, 10:17:13 PM »
now with my 1DX, im starting to feel really cheated by Canon - i really do.

my 7 year old 1D Mark IIN and 8 yr old 1D Mark II paired with a third party TC works at f/11 just fine
~ while my 1DX wont.

also - tested it on the Canon T3 - it worked - a bit slower than the 1D Mark II's but very acceptable.

      - tested on the 5D Mark II - it will AF and Lock only if you pre-focus it manually.
      - 5D Mark II without pre-focus will AF and Lock 1 out of 10 or even more - so not acceptable in any standard.

but they will work - while the 1DX wont - WTH Canon!!!!

Awesome! Glad you checked it out. Even though it doesn't fully confirm it will work with an MKIV, I may have to pick up a kenko on the chance that it might work!

neuroanatomist

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Re: Canon EOS-1D X AF at f/8 with the Kenko 1.4TC
« Reply #20 on: September 04, 2012, 10:26:31 PM »
my 7 year old 1D Mark IIN and 8 yr old 1D Mark II paired with a third party TC works at f/11 just fine
~ while my 1DX wont.

I don't suppose you have a constant f/4 lens you can try with the Kenko 2x on the 1D X, to see if it works at f/8?
EOS 1D X, EOS M, and lots of lenses
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Mt Spokane Photography

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Re: Canon EOS-1D X AF at f/8 with the Kenko 1.4TC
« Reply #21 on: September 04, 2012, 10:32:03 PM »
5.6 plus 2x = f/11 - there's no camera that AF at f/11.... :(


My 1D Mark IIN and your 1D Mark IV will work on f/8 but not f/11 - none does :)

hope this helps your inquiry.
My 1D MK III would AF at F11 with my 70-200mm f/4L and 2X TC.  My 40D also worked at F/11 with some lenses.  Obviously, you needed a non reporting TC, but it did Autofocus.

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Re: Canon EOS-1D X AF at f/8 with the Kenko 1.4TC
« Reply #21 on: September 04, 2012, 10:32:03 PM »

AJ

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Re: Canon EOS-1D X AF at f/8 with the Kenko 1.4TC
« Reply #22 on: September 04, 2012, 10:44:29 PM »
OK, to understand why this works, you need to understand the camera refuses to AF with the Canon extender because it's being told there is an f8 (or f11 for the 2X) lens on the front.  The software of the camera then declares "hell no".

The Kenko converter is passing the f stop of the lens without the change in aperture.  So the camera thinks there is an f5.6 lens on it.  Now you still need decent light and a contrasty subject, more than without the telecenter, but it still works.

Why the -1?  Because he camera is metering at f8 while being told it has f5.6.  So before the photo is taken, it is metering wrong.
Yes, but:

The camera thinks it's metering at f/5.6 and shooting at f/5.6, while the actual metering is at f/8 and the exposure is a f/8.  So - it doesn't try to control light by manipulating aperture.  So why the need to dial in compensation?

heheapa

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Re: Canon EOS-1D X AF at f/8 with the Kenko 1.4TC
« Reply #23 on: September 04, 2012, 11:58:21 PM »
This sounds the f/8 AF can be enabled by a firmware release.
Just curious what's the reason that Canon not to enable that originally?
To clear the stock for 1D Mark IV before 1DX in stock?
If the AF works well on 3rd party teleconverter, there should be an easy workaround code for a firmware fix.
If canon can send me the firmware code then I can advise the changes for them :D

TexPhoto

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Re: Canon EOS-1D X AF at f/8 with the Kenko 1.4TC
« Reply #24 on: September 05, 2012, 12:42:43 AM »
Why?  To sell more big aperture lenses?  To cut down on complaints and returns of lenses not focusing perfectly at f8 in questionable light?  Just to tick off people used to the f8 shooting?   Who knows?

My guess is some very smart engineer said: listen we can focus really really good at f5.6, or just good at f8... Which do I want to be known for?

spinworkxroy

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Re: Canon EOS-1D X AF at f/8 with the Kenko 1.4TC
« Reply #25 on: September 05, 2012, 02:16:05 AM »
Does putting a 1.4x converter on a 400 f5.6 lens mean exactly the same thing as putting a 1.4x on a 70-300 f3.5-5.6 at 300mm?

Both will be at f8 right? Unless it's not the same thing with a variable aperture zoom lens. Or maybe it's just lens specific.
Reading the article, many people have errors connectiong the Kenko 1.4 to a 5D3 with a f5.6 lens

However, my 5D3 works fine with the Kenko with a 70-300 zoom lens at 300mm f5.6 (which is f8 with the TC)….
So maybe it doesn't affect everyone and every f5.6 lens..so it depends on your luck maybe?

xps

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Re: Canon EOS-1D X AF at f/8 with the Kenko 1.4TC
« Reply #26 on: September 05, 2012, 04:14:30 AM »
Does this teleconverter work with other bodies too? 60D with 100-400mm?

My personal opinion is, that the camera producers calculate what is profitable for them. So, some features will be restricted. Many of the electronic products we use each day are capable to be more powerful than we are allowed to use by the producers.

MartinM

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Re: Canon EOS-1D X AF at f/8 with the Kenko 1.4TC
« Reply #27 on: September 05, 2012, 04:31:02 AM »
Wonder if it would also work for the 5DIII.

I have used the folowing combo

5D Mark III + TC1.4x III + TC2x II + 70-200 L IS II USM  and AF works -> 560mm ;)

But, I tried it at an airshow and AF was not fast enough to capture the fast passing aircrafts. For static birds or so, it worked fine.

Cheers
Martin

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Re: Canon EOS-1D X AF at f/8 with the Kenko 1.4TC
« Reply #27 on: September 05, 2012, 04:31:02 AM »

spinworkxroy

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Re: Canon EOS-1D X AF at f/8 with the Kenko 1.4TC
« Reply #28 on: September 05, 2012, 05:55:27 AM »
Wonder if it would also work for the 5DIII.

I have used the folowing combo

5D Mark III + TC1.4x III + TC2x II + 70-200 L IS II USM  and AF works -> 560mm ;)

But, I tried it at an airshow and AF was not fast enough to capture the fast passing aircrafts. For static birds or so, it worked fine.

Cheers
Martin

That's because your 70-200 is f2.8..even with 2x TC it's only F5.6 which is supposed to work.
The question people are asking is does the tC1.4 work when the aperture becomes f8.

For me, i don't own any prime f5.6 lens so i don't know but i've only ever tried it on a 70-300 f5.6 variable aperture zoom lens and at 300mm with the TC it works fine at f8…maybe it's because it's not a Canon lens?

SambalOelek

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Re: Canon EOS-1D X AF at f/8 with the Kenko 1.4TC
« Reply #29 on: September 05, 2012, 06:20:28 AM »
I've used Kenko 2x with the lovely Sigma 100-300 f/4 on 5D III, and it worked like a charm. Very sharp and snappy AI Servo AF with both manual and automatic.

Sigma 100-300 f/4 + Kenko 2x (effectively @ f/8) = Works 100%
Sigma 100-300 f/4 + Kenko 2x + Canon 1.4x (effectively @ f/11) = Only automatic AF point selection, fast lock
Canon EF 70-300 f/4-5.6 L + Kenko 2x (effectively @ f/8-11) = Slow/difficult to lock focus

1D X, 1D IV, 5D III, 6D, 7D, M. Assorted lenses.

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Re: Canon EOS-1D X AF at f/8 with the Kenko 1.4TC
« Reply #29 on: September 05, 2012, 06:20:28 AM »