# Ef-EFS adaptor



## Tight Knot (Aug 28, 2012)

Hi,

I bought a Kenko 2X teleconverter, and it only works on my EF lenses, not my EF-S lense. Is there an adaptor that can be used to help it work on my EF-S lenses also?

Thanks.


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## Overread (Aug 28, 2012)

Off the top of my head I don't think so. The problem is teleconverters nearly always have a protruding front element, even the Kenko has a tiny protrusion on the front element (and its the smallest there is, Canon and Sigma teleconverters have even larger front element protrusions). 

This clashes with the EFs lenses because many if not all of them have a recessed rear element. This is fine on an EFs compatible camera body as the recess pushes into the camera housing - however it means you can't use teleconverters on those lenses.


The only work around is to add space between lens and teleconverter, such as using an extension tube, however this is only suitable for closeup/macro work since adding a teleconverter removes infinity focus (and depending on the lens you can end up only able to focus a few inches from the lens). 

That said its normally not a major concern for companies either. Most EFs lenses tend to be fairly short focal lengths, so even doubling you're only getting to around 200mm which is a focal length most can afford to buy a lens for (and with the image quality drop even cheaper lenses will do better getting to 200mm over a regular lens with 2*TC). Cheap 70-300mm type lenses are also not suitable for teleconverters, again lacking the strong optics to really benefit from adding the TC. TCs are thus mostly reserved, designed and pitched at the more expensive longer and higher quality lenses - where the glass is good enough to take the image quality hit with the TC and also where the TC cost is far less than a longer lens.


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## Derrel (Aug 28, 2012)

An extension tube is your best best...but then you will not have focus to Infinity. I've read of multiple shooters using extension tubes to allow EF-S lenses to be used on all types of Canon  EOS digitals...1D, 1Ds, 5D series bodies.


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## Tight Knot (Aug 28, 2012)

Thanks for the reply Over and Derrel,
I guess the next question is whether I should just return the teleconverter. I have a few days still to return it.
I have a nice extension tube set, but I really wanted the  teleconverter for my 55-250 EFs kit lens for moon shots and long nature shots.
The lenses I have are: Canon EFS 18-55 kit lens, Canon  EFS 55-250 kit lens, Canon 70-300 (not as sharp as I like, so I don't  use it), Canon 50mm 1.4 prime lens, Canon 100mm 2.8 Macro lens, Sigma  10-20mm 4.0- 5.6 DC HSM wide angle lens.
Thanks again for the help.

Bruce.


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## Overread (Aug 28, 2012)

The only lens there I would use that TC on would be the 100mm macro - if you like higher magnification macro work (2:1) then it would have a place and if its the pro series Kenko its a good make of TC so could be worth hanging onto for when you do get a compatible lens later on.

That said if you've no real interest in boosting the magnification of your 100mm macro lens then I would return the TC yes. Better to put that money now toward saving for a proper quality longer lens (sadly longer lenses are one area where its very hard to skimp on costs - long quality optics are, sadly, expensive)


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## Tight Knot (Aug 28, 2012)

Overread said:


> The only lens there I would use that TC on would be the 100mm macro - if you like higher magnification macro work (2:1) then it would have a place and if its the pro series Kenko its a good make of TC so could be worth hanging onto for when you do get a compatible lens later on.
> 
> That said if you've no real interest in boosting the magnification of your 100mm macro lens then I would return the TC yes. Better to put that money now toward saving for a proper quality longer lens (sadly longer lenses are one area where its very hard to skimp on costs - long quality optics are, sadly, expensive)



Hi Overread,

The TC is the Kenko 2X Teleplus - 7 Element DG.

I specifically bought my extension tubes for closer Macro work. Do I need both the TC and the extension tubes? The TC cost me +- $189 on Amazon.


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## scorpion_tyr (Aug 29, 2012)

Sell those three cheap lenses you have (if you don't use them often), add a couple hundred bucks, and buy a refurbished or used Canon EF 200mm f/2.8L to use the TC on. That would be my best unless you want to spend over a grand on some serious glass, then just go big or go home with a 400mm f/2.8.


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## Big Mike (Aug 29, 2012)

Also, keep in mind that if you use a TC on your 55-250mm lens, it most likely won't auto focus.  
A TC effectively reduces your maximum aperture, a 2X will drop it about two stops.  Most cameras need at least F5.6 for the AF to function, so if you put the TC behind that lens, the maximum at 250mm will effectively be F11...and thus the AF won't have enough light to function.

That's why Canon TCs are only compatible with fast Canon lenses.


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## Big Mike (Aug 29, 2012)

On a related note, there is a way to mount EF-S lenses onto full frame or APS-H cameras, you just need to remove or alter a bit of the mounting ring.  A friend of mine did that with an EF-S 10-22mm to use it on his 1D & 1Ds.  You do have to be careful about the rear element going too far back and getting into the mirror path, and of course it will vignette, but only on the wide end of the zoom.


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## Derrel (Aug 29, 2012)

Scorpion_tyr has a good suggestion! I had kinda' forgotten about the 200mm f/2.8 Canon prime! It is priced "affordably", and is a quality lens. The other lens that might make some real sense is the 135-2 L series prime....it's got a FAST max aperture, and HIGH-quality glass. A roughly 270mm f/4...in a smallish package...oughtta be decent...

Another Canon prime, often overlooked: the 135mm f/2.8 Soft Focus...often sells very reasonably...sharp when set to no SF OFF, while soft 1, soft 2 settings are "soft-focus". SMALL! Light!

The biggest "issue" though is that MANY lenses will simply NOT COUPLE to teleconverters, due to lens rear element position and the front element positioning on TC units!!!! As I understand it though, the Sigma branded converters have somewhat "more deeply-recessed" front elements than say, NIKON TC units have, and thus the Sigma TC's will fit MANY MORE models of lenses than will TC units made by Nikon, or by Canon...


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## Tight Knot (Aug 29, 2012)

scorpion_tyr said:


> Sell those three cheap lenses you have (if you don't use them often), add a couple hundred bucks, and buy a refurbished or used Canon EF 200mm f/2.8L to use the TC on. That would be my best unless you want to spend over a grand on some serious glass, then just go big or go home with a 400mm f/2.8.


Hi Scorpion, 
I use the 18-55 and the 55-250 +-80% of the time, so no go there, but I would like to know how much I could get for the 70-300.


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## Tight Knot (Aug 29, 2012)

Derrel said:


> Scorpion_tyr has a good suggestion! I had kinda' forgotten about the 200mm f/2.8 Canon prime! It is priced "affordably", and is a quality lens. The other lens that might make some real sense is the 135-2 L series prime....it's got a FAST max aperture, and HIGH-quality glass. A roughly 270mm f/4...in a smallish package...oughtta be decent...
> 
> Another Canon prime, often overlooked: the 135mm f/2.8 Soft Focus...often sells very reasonably...sharp when set to no SF OFF, while soft 1, soft 2 settings are "soft-focus". SMALL! Light!
> 
> The biggest "issue" though is that MANY lenses will simply NOT COUPLE to teleconverters, due to lens rear element position and the front element positioning on TC units!!!! As I understand it though, the Sigma branded converters have somewhat "more deeply-recessed" front elements than say, NIKON TC units have, and thus the Sigma TC's will fit MANY MORE models of lenses than will TC units made by Nikon, or by Canon...



Hi Derrel,

Thanks for the suggestions, I will look into those lenses.


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## sovietdoc (Aug 29, 2012)

Lol "go big or go home with 400 f/2.8"

Forget about 55-250.  When you have the money, invest into 100-400L, this will probably happen when version 2 hits the market next year.  The version 1 lens will be cheap and you should be able to get a good copy of a used one for cheap.  Until then, save up because anything you buy right now will just be a temporary replacement so why waste cash..


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