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Author Topic: Kenko or Tamron 1.4x or 2x teleconverter  (Read 9155 times)

Richard8971

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Kenko or Tamron 1.4x or 2x teleconverter
« on: July 12, 2012, 02:04:24 AM »
I did a quick search so see if there was any information here regarding these teleconverters but I didn't come across anything of value so please forgive me if this question has already been asked.

I own two lenses that I would like to use with the teleconverters. My Canon EF 70-300 IS USM f4 lens and my Canon EF 70-200 IS USM f4L. Now I know the teleconverters work best with F2.8 or faster glass but I don't own a f2.8 zoom lens.

My choice would be the 2x as it would make my 70-200L a 400mm and my 300 a 600mm lens, but I am not sure what the lower light would do for the autofocus and such. The 1.4 would be OK but then I would have to use my 300 as a 400mm. (420mm to be exact)

My question is, how are the optics with these teleconverters and what exact model would you recommend? Thank you in advance to anyone who answers my question(s). Oh and one more thing, I usually shoot with an f-stop of f8 or higher (f8 ~ f13) so keeping it in the higher numbers are not a problem.

D
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Kenko or Tamron 1.4x or 2x teleconverter
« on: July 12, 2012, 02:04:24 AM »

wickidwombat

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Re: Kenko or Tamron 1.4x or 2x teleconverter
« Reply #1 on: July 12, 2012, 02:34:20 AM »
i have the kenko 1.4 optically it is comparable to the canon but does not have weather sealing
however it will also work on any lens including the 100 f2.8L macro

quite a few others here use this TC too for the money its the best and most versitile
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Re: Kenko or Tamron 1.4x or 2x teleconverter
« Reply #2 on: July 12, 2012, 02:46:47 AM »
I own two lenses that I would like to use with the teleconverters. My Canon EF 70-300 IS USM f4 lens and my Canon EF 70-200 IS USM f4L. Now I know the teleconverters work best with F2.8 or faster glass but I don't own a f2.8 zoom lens.

My choice would be the 2x as it would make my 70-200L a 400mm and my 300 a 600mm lens, but I am not sure what the lower light would do for the autofocus and such. The 1.4 would be OK but then I would have to use my 300 as a 400mm. (420mm to be exact)

My question is, how are the optics with these teleconverters and what exact model would you recommend?

OK, so firstly, i'm presuming you have the 70-300 IS USM f/4-5.6 non-L (although these answers will be exactly the same if you do have the L).

Now, there are two types of teleconverters, reporting and non-reporting. When you mount a 200mm f/4 lens with a 2x Teleconverter, you get a 400mm f/8 (because that's how t/cs work). Now, a reporting-teleconverter will tell the camera that you have a 400mm f/8 lens, a non-reporting t/c will tell the camera that you have a 200mm f/4 lens.

Mounting a 2x Teleconverter on the 70-300 will bring it to f/8-f/11, and mounting a 2x T/C on the 70-200 f/4 will give you a 140-400mm constant f/8.

Now, if you use a reporting teleconverter, using a 2x t/c, unless you have a 1D, 1Ds, 1V, or 3, your autofocus is NOT going to work, at all. If you do have one of these bodies, you will get autofocus only at the centre AF point (better than nothing). Using a reporting t/c on a 1/3-series, the camera will slow the Autofocus motor down so that it's more accurate.
If you use a non-reporting teleconverter, the camera will still think you have an f/4 or f/4-5.6 lens. So it will happily *try* to autofocus. Whether it succeeds or not is debateable. I use my 70-300L with a non-reporting Kenko 1.4x Pro300DG sometimes. On my 7D, the autofocus tries and fails to AF a lot (normally I leave it to MF). On my EOS 3, autofocus *should* work, because the centre point is f/8 sensitive, and the lens + t/c is f/8 at the long end. But because the camera doesn't know about the teleconverter, it runs the AF motor at full speed and most of the time it misses focus and has to wobble about a bit before it locks. If you're using a 2x t/c, that problem will be even worse, and you're probably better off just using MF anyway.

So, what should you get?
If you have a 1D or 1Ds (not 1DX), you can try to use a 2x reporting T/C, and you may get AF at the 70mm end of the 70-300, or on the whole of the 70-200 f/4.
If you have a lesser body, I'd be sticking with a 1.4x t/c on the 70-200 only if you want AF, anything else you'll have to MF.

As for IQ, a lot of people just steer clear of 2x teleconverters as a matter of course. Some are definitely better than others though.
I've got the Kenko Pro300 1.4x DG teleconverter, it's a non-reporting t/c for 7-pin lenses like the 70-300L (and 70-300 non-L), but it reports for 10-pin lenses like 70-200 L and 100-400L. There's only one above it in the Kenko range, the newer DGX version (which afaik is a reporting t/c all the time, someone feel free to correct me on that).
Image quality is always subjective, I think it's fairly good with my 70-300L attached (I used to own the 70-300 non-L, and I didn't like the IQ at 300mm even without a teleconverter. If you think that it's ok, you may be ok with using a t/c on it too).
As for Tamron, someone else can answer on that, I've never used them...
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Re: Kenko or Tamron 1.4x or 2x teleconverter
« Reply #3 on: July 12, 2012, 04:38:26 AM »
I've got the Kenko Pro300 1.4x DG teleconverter, it's a non-reporting t/c for 7-pin lenses like the 70-300L (and 70-300 non-L), but it reports for 10-pin lenses like 70-200 L and 100-400L. There's only one above it in the Kenko range, the newer DGX version (which afaik is a reporting t/c all the time, someone feel free to correct me on that).

The confusion about Kenko tcs is very big due to different "official" versions (dg and dgx) and next to this Kenko might silently update their products (different ean numbers). There are some threads on this if you're looking for specific lenses, but your 70-200/4 and 70-300/4-5.6 should be ok - somehow Kenko dgx manages to make the camera body af @f8 even though the manual says different. That being said, plugging a tc on a 70-300 non-L is a very bad idea, it's better to just crop.

Image quality is always subjective, I think it's fairly good with my 70-300L attached (I used to own the 70-300 non-L, and I didn't like the IQ at 300mm even without a teleconverter. If you think that it's ok, you may be ok with using a t/c on it too).

+1 ... iq on the 70-300L is "good", but I a 2x tc would degrade the iq too much for me. The af @f8 on my 60d is working, but definitely more prone to hunting, single-point af needs much light/contrast, multi-point af is ok.

Richard8971

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Re: Kenko or Tamron 1.4x or 2x teleconverter
« Reply #4 on: July 12, 2012, 10:29:27 PM »
Thank you for the information everyone. It was exactly what I was looking for.

Guess it's just time to save up and get the EF 100-400L!!! :)

The TC's just don't seem worth the time for f4 lenses. (sigh)  :'(

D
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wickidwombat

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Re: Kenko or Tamron 1.4x or 2x teleconverter
« Reply #5 on: July 12, 2012, 11:42:19 PM »
Thank you for the information everyone. It was exactly what I was looking for.

Guess it's just time to save up and get the EF 100-400L!!! :)

The TC's just don't seem worth the time for f4 lenses. (sigh)  :'(

D

sticking a kenko 1.4 on a 100-400 will still produce excellent image if you stop down 1 extra stop
if you get a DG (all the new ones are DGX, reporting ones) old ones are DG but have the same optics apparently
so the max aperture will be f8 however if you stop down to f11 the image quality will still be excellent and give you 560mm equivalent on a full frame camera 896 on a crop! and 728 on an APS-H 1D which retain autofocus  :)
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Re: Kenko or Tamron 1.4x or 2x teleconverter
« Reply #6 on: July 14, 2012, 06:22:42 PM »
I have both a Kenko 1.4x DG Pro and a Tamron 2x SP 300 Pro.

I got the Tamron 2x because I won a pretty cheap ebay auction.  Its image quality is actually pretty good (save for some CA)..  Stopping down 1.5 stops is about the same sharpness as wide open without the TC.  You do lose some contrast, but you can pull it back in post processing no problem..  The main problem I have with the 2x is autofocus, though..  It likes to hunt a lot, if there's not maaajor contrast with what I'm shooting at.  I'll do a lot of manual focus with it, though, no problem.  But good luck with fast-moving stuff...

The Kenko 1.4x I got years ago, and it's great.  It's a little sharper than the Tamron 2x, and a bittt better with CA, but still has a fair amount of CA..  So you just need to be aware of where/what you're shooting.  It's got better contrast, for sure, too.  I was more impressed with the 2x that it was so near optically to the 1.4x, after reading all sorts of stuff about 2x complain-complain over the years.  I'd say the autofocus is its main problem.

The Kenko 1.4 will do a similar hunting with non f/2.8 lenses, and even with my Sigma 120-300, autofocus speed slows way down.  And as someone mentioned, the 1.4x plus the 70-300 IS non-L @ 300 is definitely NOT sharp.  Even stopped down, it leaves something to be desired..  But the 70-300@300 isn't sharp in the first place, so you can't expect tooo much.  (Really its fine for web-sized photos, though..) Also, it'll hunt like crazy @300, but still try to autofocus..  (essentially it's trying to autofocus at f/8...).

They are both pretty available on eBay, and I've seen them go for anywhere from 50-120-ish...  Totally random!  Even if you get a 100-400, I would recommend you pick up a 1.4x, if for no other reason than a little bit of fun, and a little bit of "just in case"..  It's like an inch thick with end caps..  Definitely worth it having it in the bag, if you ask me!  The 2x is significantly larger, and less able to squeeze into the bag unnoticed..  So I'm less inclined to encourage you to go get a 2x.

When I have nothing better to do, I like to stack them, and go crazy..  Interestingly, if the 1.4x is in front of the 2x, I lose 3 stops of light.  But if the 2x is in front of the 1.4x, I only lose 2 stops of light..  But in the latter case, the image quality is poorer, and I need to stop down extra, anyway...   : D

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Re: Kenko or Tamron 1.4x or 2x teleconverter
« Reply #6 on: July 14, 2012, 06:22:42 PM »