# No 2X extender for 70-300mm L Series



## TexinAfrica (Mar 19, 2012)

I just found out that the Canon externders (models II or III) will work with most ranges of zooms but not the 70-300mm L series. I assume this must be due to it's "trombone" design or some issue related to it's compace size. Can someone elaborate???? Thanks.


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## neuroanatomist (Mar 19, 2012)

The Canon extenders have a front element that protrudes forward, so a complatible lens must have a space between the lens mount and the rear element (i.e. the rear element must be recessed) for the lens to be compatible with the extender. The 70-300mm L has a rear element that comes right to the lens mount. 

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.


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## jalbfb (Mar 19, 2012)

neuroanatomist said:


> The Canon extenders have a front element that protrudes forward, so a complatible lens must have a space between the lens mount and the rear element (i.e. the rear element must be recessed) for the lens to be compatible with the extender. The 70-300mm L has a rear element that comes right to the lens mount.
> 
> 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.



I have the Kenko x1.4 and it works just fine with my 70-300L just as neuro stated. It's a lot less in price as well compared to Canon extenders


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## smirkypants (Mar 19, 2012)

neuroanatomist said:


> 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.


I hate to be a conspiracy theorist, but it seems lots of things that Canon is doing lately is to push people to buy more expensive equipment. The f8 problem keeps people from putting extenders on lower-priced f4 and f5.6 zooms, and the 70-300 won't take an extender at all. 

Just, you know, sayin'...


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## 5dmk.iii (Mar 19, 2012)

smirkypants said:


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



Agree all they way. Crippling the F8 AF was very low from Canon. Push the pros who can afford it, but for the hobbyists, it's cruel.... 

Just as a side note: there's a review of the 70-300L, where Mr. Farace HAS used the 2x iii with the 70-300mm albeit in MF mode and fixed to 300mm (so that there is no love making between the 2x protruding element and rear element of the 70-300L).

http://www.shutterbug.com/content/canon-ef-70-300mm-f4-56l-usm-long-short-it

Beware though: if used in AF more or less than 300mm, you could damage the lens or the extender... so I would not recommend doing it unless you know what you are doing. In this lens, the element moves during focussing as well, so even in MF mode... be very careful !


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## Mt Spokane Photography (Mar 19, 2012)

smirkypants said:


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


 
There are a lot of Canon patents for the rear lens focusing. They are supposedly able to make a lens smaller, lighter and with improved IQ, but the Canon TC compatibility is lost.

Since its mostly a f/5.6 lens, A TC is not going to AF except with the older 1D series bodies. 

It is a compromise. Do you want big, heavy, and more distortion, or give up TC compatibility. I'll take losing Canon TC compatability, since I can get a Kenko. There is no work around for the weight, size, and IQ.


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## Marsu42 (Mar 20, 2012)

Mt Spokane Photography said:


> smirkypants said:
> 
> 
> > I hate to be a conspiracy theorist, but it seems lots of things that Canon is doing lately is to push people to buy more expensive equipment. The f8 problem keeps people from putting extenders on lower-priced f4 and f5.6 zooms, and the 70-300 won't take an extender at all.
> ...



We had these discussion just 1-2 weeks ago (use the search ) - you can get the Kenko and tape some pins to get f8 af, but it will be slow. So Canon might not have done this just for marketing purposes, but also to prevent people stating that their bodies have a crappy (f8) af. But of course, Canon wants to sell their expensive stuff, thus the 70-300L has some iq drawbacks on ff. 

In general, I got the 70-300L since about one month and am extremely happy with it. It's no "shoot in the dark lens", but these have a very thin dof to begin with, but it's got a very good size-weight-iq-af-zoomfactor-buildquality-price combination.


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## dr croubie (Mar 20, 2012)

Marsu42 said:


> you can get the Kenko and tape some pins to get f8 af, but it will be slow.



Actually, since I got the Kenko (Pro300 DG, there's a lot of other different versions, your experience may vary) 1.4x, I've figured out that you don't even need to tape pins.

If the lens takes canon extenders (ie like a 70-200L), then it has 10 pins.
If it has 10 pins, then the kenko converter will translate Fmm and f/ properly, ie 70-200 f/4 becomes 100-280 f/5.6.
If it has 7 pins (like my 70-300L), then the kenko is "invisible" to the camera, ie, the EXIF data still reads 300mm f/5.6, even though it's 420mm f/8 in reality.
So the camera "tries" to AF, but unless it's in very bright sunlight (even if it is), it hunts and fails a lot because the aperture is just too narrow (for my 7D at least).

But hey, seeing as I already had the 70-300L, adding an extra $100 wasn't bad for a Manual Focus 420mm f/8 IS lens on top.


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## Marsu42 (Mar 20, 2012)

dr croubie said:


> Marsu42 said:
> 
> 
> > you can get the Kenko and tape some pins to get f8 af, but it will be slow.
> ...



Afaik, only the updated "DGX" converters need the taping hack since they modify the lens' (exif) data. But since you've got the 70-300L too: Have you used it on a crop camera? How is the iq - does it worsen so much that it's better to stay @300mm, keep the af and crop the picture?


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## wickidwombat (Mar 20, 2012)

if you can find an older kenko DG 1.4 teleconverter that does not report aperture it will still report the lens as f5.6 to the camera and you will keep AF but i think it will slow down
the new current model DGX converters report aperture so need the f8 AF of a 1D I used the kenko DGx with my 28-300 and 1D3 for ages and it worked great so i imagine the 70-300 will be just fine too.


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## briansquibb (Mar 20, 2012)

A 2x would make it F11. Not very useful methinks as you are talking of defraction before you start

The Tenko 1.4 is fine on the 1D4


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## TexinAfrica (Mar 20, 2012)

I appreciate the help from all. I'm a bit new to this process so let me clarify. I understand the Canon TC will not work. Several explained why. Thanks.

However, it appears the Kenko 1.4 will work but struggles with auto focus in dim light. It will work fine on manual focus? I would prefer to avoid taping any conductors (it's that anal engineer in me) Thanks from lovely downtown Luanda, Angola.


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## brianwallace21 (Mar 20, 2012)

I've owned a host of teleconverters including both the DG and DGX Kenko models.

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. 

If you buy any other reporting teleconverter (Tamron SP, Kenko Teleplus Pro DG) you would need to tape pins. 

If you buy any other non-reporting teleconverter you won't need to worry about it. 

My suggestion is the buy the Kenko Teleplus Pro 300 1.4x DGX teleconverters. No taping, but your EXIF data will be correct.


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## Marsu42 (Mar 20, 2012)

TexinAfrica said:


> However, it appears the Kenko 1.4 will work but struggles with auto focus in dim light. It will work fine on manual focus?



Of course mf will work fine - but personally, I'd find that tricky for wildlife and the standard viewfinder screen of my 60d which makes the dof larger than it actually is (this problem has gotten me a lot of "what did I think?" pictures).

Afaik, the problem with af and small aperture is not (only) that the little light left, but that the *phase* af gets problems while *contrast* af in live view might work fine.



wickidwombat said:


> the new current model DGX converters report aperture so need the f8 AF of a 1D I used the kenko DGx with my 28-300 and 1D3 for ages and it worked great so i imagine the 70-300 will be just fine too.



... and ...



wallybarthman said:


> 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!


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## DianeK (Mar 20, 2012)

Marsu42 said:


> But since you've got the 70-300L too: Have you used it on a crop camera? How is the iq - does it worsen so much that it's better to stay @300mm, keep the af and crop the picture?



I find the IQ even at 300mm is very good and so I just crop instead of using an extender. I have a 60D. The image below is a severe crop, only 1/3 the original size.
Diane


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## Marsu42 (Mar 20, 2012)

DianeK said:


> 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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## DianeK (Mar 20, 2012)

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


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## briansquibb (Mar 20, 2012)

The best 2x converter is a 600


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## shtfmeister (Mar 20, 2012)

smirkypants said:


> neuroanatomist said:
> 
> 
> > 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?


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## Marsu42 (Mar 20, 2012)

briansquibb said:


> 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...


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## Mt Spokane Photography (Mar 21, 2012)

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.


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## brianwallace21 (Mar 21, 2012)

wallybarthman said:


> 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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## Marsu42 (Mar 21, 2012)

wallybarthman said:


> 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


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## brianwallace21 (Mar 23, 2012)

Marsu42 said:


> 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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