# Canoner Has Questions - Extender Stacking



## Mesh1DMarkIV (Feb 8, 2012)

I currently own a Canon 70-200mm f2.8L USm IS II lens.  I also own 2 Lens extenders..1.4X and 2.0x.  Is it safe for me to stack these extenders on to the Canon lens?  Canon 70-200mm + 1.4x +2.0x?

I also own Canon 24-105mm F4L, Canon 24-105 f2.8L and canon 100mm f2.8L lens - can I use canon extenders on these lenses?  Thank you for your advice.


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## KmH (Feb 8, 2012)

Why would you want to? 

The loss of image quality and the 3 stop loss of effective lens aperture would suck.

f/2.8 would effectively become f/8 and f/4 would effectively become f/11.


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## MLeeK (Feb 8, 2012)

Yes, you CAN do it. You just wouldn't want to.


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## Mesh1DMarkIV (Feb 8, 2012)

Thank you for your reply.  Apart from Loosing 3 stops do you think it might interfere with the elctronics of the Camera


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## mjhoward (Feb 8, 2012)

Mesh1DMarkIV said:


> Thank you for your reply.  Apart from Loosing 3 stops do you think it might interfere with the elctronics of the Camera



No you can stack them safely.  I've done it several times with (2) 2x Extenders and an 800mm f/5.6.  Works just fine, you'll lose AF and the photos will be softer but it won't damage your camera or lens.  They're made to work stacked.


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## mjhoward (Feb 8, 2012)

BTW, there is a massive difference in the Extender II's and the new Extender III's, at least when coupled with the new 400mm f/2.8 II.  That combo was almost indistinguishable in sharpness from the 800mm prime.


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## Mesh1DMarkIV (Feb 8, 2012)

Does that mean that the Canon Extenders II are better than the III extenders or vice versa?


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## mjhoward (Feb 8, 2012)

Extender III is significantly better than II.  Keep in mind though that teleconverters work best on longer, high quality primes.  They probably wont do so well on something like 24-70 or even the 70-200.  That is just a guess though as I've never used the teleconverters on those lenses, only the 800mm and new 400mm II.


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