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Author Topic: Teleconverters/Extenders, Canon or Kenko?  (Read 2637 times)

bholliman

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Teleconverters/Extenders, Canon or Kenko?
« on: July 01, 2013, 10:40:09 AM »
I've been looking at purchasing a 1.4 and/or 2.0 extender.  I have just been considering the Canon EF 1.4X III and EF 2.0X III, but then read that the Kenko Pro TC's were just as good if not better.

Any insight?
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Teleconverters/Extenders, Canon or Kenko?
« on: July 01, 2013, 10:40:09 AM »

neuroanatomist

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Re: Teleconverters/Extenders, Canon or Kenko?
« Reply #1 on: July 01, 2013, 11:07:01 AM »
I have both the Canon 1.4xIII and 2xIII.  I have read that the Kenko 1.4x is 'as good' as the Canon 1.4xIII in some reviews, others indicate that it's as good as the 1.4xII and a little short of the 1.4xIII.  I have not read many reviews of the Kenko 2x, but the few I've seen suggest it's not nearly as good as the Kenko 1.4x or any Canon 2x.

The other issue with Kenko TCs is compatiblity.  They come in different firmware versions, indicated by colored dots on the TC.  They cannot be updated.  Many users have reported issues with certain combinations of Kenko TCs and Canon bodies + lenses.  One apparently reproducible issue occurs with the latest Kenko 1.4x and the 5DIII - if you have AFMA enabled, the camera locks up and you need to pull the battery to reset it.  The 'solution' is to not use AFMA with the Kenko TC...and IMO, that's no solution at all unless you're lucky enough that your combo doesn't need it (and no guarantee that will be true with the next lens you try).

The only reason to go with a Kenko TC, IMO, is if you require it for a lens like the 70-300L or 100L Macro, where the Canon TC's won't work for physical reasons.  But personally, I'd recommend going with the Canon TCs and sticking with compatible lenses.
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Re: Teleconverters/Extenders, Canon or Kenko?
« Reply #2 on: July 01, 2013, 11:28:15 AM »
I have both the Canon 1.4xIII and 2xIII.  I have read that the Kenko 1.4x is 'as good' as the Canon 1.4xIII in some reviews, others indicate that it's as good as the 1.4xII and a little short of the 1.4xIII.  I have not read many reviews of the Kenko 2x, but the few I've seen suggest it's not nearly as good as the Kenko 1.4x or any Canon 2x.

The other issue with Kenko TCs is compatiblity.  They come in different firmware versions, indicated by colored dots on the TC.  They cannot be updated.  Many users have reported issues with certain combinations of Kenko TCs and Canon bodies + lenses.  One apparently reproducible issue occurs with the latest Kenko 1.4x and the 5DIII - if you have AFMA enabled, the camera locks up and you need to pull the battery to reset it.  The 'solution' is to not use AFMA with the Kenko TC...and IMO, that's no solution at all unless you're lucky enough that your combo doesn't need it (and no guarantee that will be true with the next lens you try).

The only reason to go with a Kenko TC, IMO, is if you require it for a lens like the 70-300L or 100L Macro, where the Canon TC's won't work for physical reasons.  But personally, I'd recommend going with the Canon TCs and sticking with compatible lenses.

+1.  I was writing something similar but neuroanimist beat me to it.  I too have the Canons -- one bought on sale, the other used.  Using them on my 70-200 II required AFMA (my bare lens required AFMA too but it was a different value with the extenders attached).  Canon bodies also have different settings for the bare lens and with the extender attached, so it is convenient.  I didn't think that using the 70-200 + 2x (since I was using it at f/5.6 and f/8) would require AFMA but it did -- I was very surprised.

Another point is Canon III extenders don't stack because of the protrusion (perhaps it's for weather resistence, but probably more for preventing us from using them in ways they weren't designed -- Murphy-proofing).

neuroanatomist

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Re: Teleconverters/Extenders, Canon or Kenko?
« Reply #3 on: July 01, 2013, 11:57:21 AM »
Another point is Canon III extenders don't stack because of the protrusion (perhaps it's for weather resistence, but probably more for preventing us from using them in ways they weren't designed -- Murphy-proofing).

It's the extra elements in the 2xIII.  You can still stack a 1.4xIII behind a 2xII.  With the MkIII extenders, you can put a 12mm extension tube between them to stack...if you're willing to take the IQ hit from stadking, that is...
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Re: Teleconverters/Extenders, Canon or Kenko?
« Reply #4 on: July 01, 2013, 12:29:47 PM »
Another point is Canon III extenders don't stack because of the protrusion (perhaps it's for weather resistence, but probably more for preventing us from using them in ways they weren't designed -- Murphy-proofing).

It's the extra elements in the 2xIII.  You can still stack a 1.4xIII behind a 2xII.  With the MkIII extenders, you can put a 12mm extension tube between them to stack...if you're willing to take the IQ hit from stadking, that is...

Do you know if it is still possible to focus on distant subjects if you use a 300 f2.8 +2xIII , 12mm extension tube and 1.4 converter?

If it works 'reasonably' well it could be worth the price of the extension tube, since they are pretty inexpensive.

neuroanatomist

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Re: Teleconverters/Extenders, Canon or Kenko?
« Reply #5 on: July 01, 2013, 12:33:43 PM »
Do you know if it is still possible to focus on distant subjects if you use a 300 f2.8 +2xIII , 12mm extension tube and 1.4 converter?

No idea.  I've tried with my 600/4, and even though only one of the extenders is reported, AF doesn't work (it isn't disabled as it would be with an f/11 reported max aperture, but it just racks the focus back and forth and fails to lock onto anything).  Contrast detect AF does work, though. 

But that's with an f/4 lens.  I could try the two extenders with the EF 12 between them on my 70-200/2.8L IS II, if you like. 
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Re: Teleconverters/Extenders, Canon or Kenko?
« Reply #6 on: July 01, 2013, 02:04:49 PM »
Do you know if it is still possible to focus on distant subjects if you use a 300 f2.8 +2xIII , 12mm extension tube and 1.4 converter?

No idea.  I've tried with my 600/4, and even though only one of the extenders is reported, AF doesn't work (it isn't disabled as it would be with an f/11 reported max aperture, but it just racks the focus back and forth and fails to lock onto anything).  Contrast detect AF does work, though. 

But that's with an f/4 lens.  I could try the two extenders with the EF 12 between them on my 70-200/2.8L IS II, if you like.

If you got the time to do that , yes please !
I have read about extension tubes that they can make you lose infinity focus/focus possibility at large distances.
But I am not sure if that is also the case with the 12 mm , or just the longer ones.

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Re: Teleconverters/Extenders, Canon or Kenko?
« Reply #6 on: July 01, 2013, 02:04:49 PM »

fegari

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Re: Teleconverters/Extenders, Canon or Kenko?
« Reply #7 on: July 01, 2013, 02:30:43 PM »
Good advices in this post.

I personally have zero hesitations bying third party lenses but when it comes to a TC, I don't even considered non canons.

Not only the compatibility issues there may be butt from all I've ever read about it no 3rd party has better optical quality (maybe the 1.4 could  matched apparently). Additionally with the AF speed penalty you take with a TC, almost certainly the Canon's will slow the least.

Get the canon's .=)

(I have 1.4II and 2xIII)

mwh1964

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Re: Teleconverters/Extenders, Canon or Kenko?
« Reply #8 on: July 01, 2013, 02:55:21 PM »
Recently got the 2x mk3 to work with a 70-200 mk2. To my very surprise it works really well. Quick AF and good IQ. It makes your lens combo heavier and longer though. The color on the TC is different to my zoom though.  I wouldn't recommend buying 3rd party TC. Then rather purchase a refurbished canon model when they become available, mk 2 or 3 that is. I wasn't sure if I would keep the TC, but after trying it I am confident in the quality provided and will keep it. Good luck choosing.
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tron

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Re: Teleconverters/Extenders, Canon or Kenko?
« Reply #9 on: July 01, 2013, 03:49:28 PM »
Another point is Canon III extenders don't stack because of the protrusion (perhaps it's for weather resistence, but probably more for preventing us from using them in ways they weren't designed -- Murphy-proofing).

It's the extra elements in the 2xIII.  You can still stack a 1.4xIII behind a 2xII.  With the MkIII extenders, you can put a 12mm extension tube between them to stack...if you're willing to take the IQ hit from stadking, that is...
This is a very interesting piece of information. Unfortunately it seems to me that the weakest link in IQ is the EF2X II so if I were to upgrade I would first replace that very lens.

neuroanatomist

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Re: Teleconverters/Extenders, Canon or Kenko?
« Reply #10 on: July 01, 2013, 10:50:32 PM »
If you got the time to do that , yes please !
I have read about extension tubes that they can make you lose infinity focus/focus possibility at large distances.
But I am not sure if that is also the case with the 12 mm , or just the longer ones.

AF with the TC's stacked and the EF 12 tube between them works with the 70-200/2.8 II...sort of.  It will lock focus on high contrast subjects, but not on low contrast subjects or in dimmer light.  It didn't matter in which order the TCs were stacked. With the zoom, the usable focus distance range is restricted especially at the short end (which makes sense in that tube effectiveness is inversely proportional to focal length - it wouldn't be as bad with a 300mm lens).

I'd say that although it is able to lock focus sometimes, it's really not robust with the stacked TCs on the f/2.8 lens, at least with the zoom.
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bholliman

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Re: Teleconverters/Extenders, Canon or Kenko?
« Reply #11 on: July 02, 2013, 12:30:05 AM »
Sounds like I need to stick with Canon.  I want the maximum image quality, decent AF performance and no compatability issues.  Thanks for the input.
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Re: Teleconverters/Extenders, Canon or Kenko?
« Reply #11 on: July 02, 2013, 12:30:05 AM »