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Author Topic: No 2X extender for 70-300mm L Series  (Read 7655 times)

Marsu42

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Re: No 2X extender for 70-300mm L Series
« Reply #15 on: March 20, 2012, 12:58:23 PM »
I find the IQ even at 300mm is very good and so I just crop instead of using an extender.

I've got the 70-300L on 60d, too, so I know its iq @300mm is good. But did you *ever* try the Kenko w/ this lens? The question is if cropping outperforms a non-cropped tc shot if a zoom length of 420mm is really needed. Iso nose for one thing becomes more apparent when cropping which makes me think of a tc for some occasions.

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Re: No 2X extender for 70-300mm L Series
« Reply #15 on: March 20, 2012, 12:58:23 PM »

DianeK

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Re: No 2X extender for 70-300mm L Series
« Reply #16 on: March 20, 2012, 01:03:26 PM »
Here's another that's about 60% of original size.  Beats fiddling with extenders IMHO. Edit: just saw the previous post - no I haven't actually tried the Kenko...I like to keep things simple ;)
Diane
« Last Edit: March 20, 2012, 01:09:47 PM by DianeK »

briansquibb

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Re: No 2X extender for 70-300mm L Series
« Reply #17 on: March 20, 2012, 02:02:58 PM »
The best 2x converter is a 600  ;) ;) ;)

shtfmeister

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Re: No 2X extender for 70-300mm L Series
« Reply #18 on: March 20, 2012, 02:58:18 PM »
Canon extenders are compatible only with L-series primes of 135mm and longer, and L-series zooms starting at 70mm, with the exception of the 70-300 L.  There are 3rd party extenders (e.g. Kenko) that do not have the protruding element and are compatible with most Canon lenses.


If the extender has glass that sticks out why not put an extention tube between it and the lens to make more room?
« Last Edit: March 20, 2012, 03:05:37 PM by shtfmeister »

Marsu42

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Re: No 2X extender for 70-300mm L Series
« Reply #19 on: March 20, 2012, 03:09:58 PM »
The best 2x converter is a 600  ;) ;) ;)

Please, people, I know karma's gone and imho it's a great thing - but it really would be interesting to know which lenses are qualified for extender use when ignoring the af problem. Esp. as briansquibb noted a tc is poor man's 600 tele. Tc will be lowered a bit as well as iso noise because of less need to crop.

Now you wouldn't want to put a tc on a 70-300 non-L, it does work with the 70-200L, but I'm still wondering about the 70-300L. Problem is I cannot just try it it in a shop myself since I guess the Kenko is "boxed" and I either buy it (and then return it) or someone comes up with a smart answer here...

Mt Spokane Photography

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Re: No 2X extender for 70-300mm L Series
« Reply #20 on: March 20, 2012, 08:43:26 PM »
I've used non reporting extenders on many different lenses and bodies.  There is no pattern that I can find to determine what will work with any given body.  There is enough variation body to body apparently, that some bodies work, and another body of the same model won't.
 
My old 40D was one of the best I've seen for focusing at f/8 or even f/11.  My 1D MK III would sometimes focus at f/11, but very slow, but manually pre-focus to the approximate area and it would snap in instantly.
 
You just have to try, but don't overlook manually focusing first, and then seeing if AF will lock on.
 
My 70-200mm f/4L IS seemed to be pretty good focusing on some bodies at f/8 or even f/11.  I could stack a 1.4 and 2X on it and often it will focus fine.
 
I'm interested in seeing how the 5D MK III does with its -2 EV low light AF capability.

wallybarthman

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Re: No 2X extender for 70-300mm L Series
« Reply #21 on: March 21, 2012, 09:32:30 AM »
If you buy the newest models (DGX) you do not need to tape pins.  The aperture and focal length will still report correctly but the Kenko does not cause the AF to be deactivated. 

@wallybarthman: Are you using a 1d body which does af @f8? Because what you're saying is the opposite of everything else I ever read of putting a 1.4x tc on a 5.6 lens and using it on a non-1d eos body!
[/quote]

I am not - this is on a 7D.

Kenko changed how the TCs report when they moved from the DG to the DGX series.  The DG series (and I owned a 2x DG model) would disable autofocus if it went above f5.6.  However, the new DGX series TCs do not disable autofocus.  In fact, I can stack teleconverters (Canon 2x, Kenko 2x, Kenko 1.4x) on my 200 f2.8 and it reports the correct aperture (f16 in this case) and still does not disable autofocus. 

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Re: No 2X extender for 70-300mm L Series
« Reply #21 on: March 21, 2012, 09:32:30 AM »

Marsu42

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Re: No 2X extender for 70-300mm L Series
« Reply #22 on: March 21, 2012, 11:36:38 AM »
Kenko changed how the TCs report when they moved from the DG to the DGX series.  The DG series (and I owned a 2x DG model) would disable autofocus if it went above f5.6.  However, the new DGX series TCs do not disable autofocus.

Ok, this contradicts what I've read before, but I guess I believe you since you have a 7d. To make dead sure: We are talking about the "Kenko 1.4X PRO 300 Teleconverter DGX for Canon EOS Digital SLRs", are we:

http://www.amazon.com/Kenko-1-4X-Teleconverter-Canon-Digital/dp/B002C6QC3E/ref=sr_1_1?ie=UTF8&qid=1332344013&sr=8-1

wallybarthman

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Re: No 2X extender for 70-300mm L Series
« Reply #23 on: March 23, 2012, 04:30:51 PM »


Ok, this contradicts what I've read before, but I guess I believe you since you have a 7d. To make dead sure: We are talking about the "Kenko 1.4X PRO 300 Teleconverter DGX for Canon EOS Digital SLRs", are we:

http://www.amazon.com/Kenko-1-4X-Teleconverter-Canon-Digital/dp/B002C6QC3E/ref=sr_1_1?ie=UTF8&qid=1332344013&sr=8-1

That's the one!

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Re: No 2X extender for 70-300mm L Series
« Reply #23 on: March 23, 2012, 04:30:51 PM »