Photography / Hands-on Review

Canon Extender EF 1.4x III & Extender EF 2x III


Tele-extenders are terrific tools for increasing the focal length of your current lenses without taking up valuable space or adding additional weight to your camera bag, and if you're a Canon shooter, you might be interested to know about the new Extender EF 1.4x III and Extender EF 2x III tele-converters.

Canon's Extender EF 1.4x III and Extender EF 2x III multiply the focal lengths of most Canon normal, macro and telephoto lenses by a factor of 1.4x and 2x respectively. Both extenders contain built-in microcomputers that provide seamless functionality between Canon (D)SLRs and lenses. Other features found on and within each of these new  tele-extenders are Fluorine lens coatings and weather- and dust-proof construction. The Canon Extender EF 1.4x III and Canon Extender EF 2x III are expected to be available in December, 2010, for an approximate retail price of $500.

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I'm shooting with 70-200 f2.8 and 100-400mm f4.6 L-series lenses using a 5D body. I'm interested in 1.4x teleconverter, but am concerned about camera shake, especially when losing a stop on the slower f4.6 lens. Can you give me any advice in this regard as my shooting environment typically doesn't allow a tripod. 

If shooting hand held, you would likely need to shoot with a shutter speed at least 1-stop faster than you typically do when you add the 1.4X teleconverter. If you are shooting in areas that aren’t suited for a tripod, you might consider a monopod.

what extender lens work with cannon EFS 55-250mm

The Kenko TELEPLUS HD DGX  Teleconverters for Canon EF/EF-S would be compatible with the Canon EF-S 55-250mm lenses.  Though, autofocus will most likely be lost when using a teleconverter with that lens due to the loss of light when using teleconverters.

I have tried the Canon 2X III tele extender with my Canon 500 mm and my Canon 70-200 mm lenses. The tele extender with both lenses does indeed give you a2 X large image that appears quite good--good until you put it on the computer and carefull evaluate the images. Upon evaluation, I found I got considerably better quality by cropping and expanding the image from the original lenses than with the tele extender. Anyone who says the quality is excellent simply needs to evaluate in more detail. I am shipping by tele-extender back to B&H. Fortunaltely, they are a great company willing to accept returns. I took multiple photos of wildlife and tested it with other images before I decided to return it. I really did want it to work--just too good to be true.


I am using Canon EF 70-200 F/4L IS with EOS6D...Will 2X be a better choice than 1.4X in terms of autofocus & IQ & sharpness at lower fstops? Please advise...



Depending on your camera, autofocus might not be possible using the 70-200mm f/4 with the 2X extender.  Unless your camera is f/8 capable, you would need to go with the 1.4X converter in order to retain autofocus.  Otherwise, which teleconverter to go with would depend on how much extra reach you wanted from your lens: you would get better results using the 2X converter, than the 1.4X converter and cropping.

I have the Canon 5D IV, and original Canon 100-400 L , will the 2X Canon exender III autofocus the 100-400?

Unfortunately, autofocus would not be possible using a 2X teleconverter with the 100-400mm lens on the 5D IV.  If you wanted to retain autofocus, you would need to use the Extender EF 1.4x III.

Can I use the Extender EF 2x III tele-converter with the ​Canon EF-S 55-260mmm F/4-5.6 IS II Lens?

Unfortunately not. The Canon Extender EF 2X III is only compatible with select EF mount lenses, and would not work with the Canon EF-S 55-250mm f/4-5.6 IS II Lens.

Can I use the Extender EF 2x III tele-converter with the ​Canon EF 200mmm F/2.8L II USM Lens?

The Canon Extender EF 2x III will be compatible with the Canon EF 200mm F/2.8L II USM Lens, yes.

Can I use the Extender III 2x on the Canon EF 75-300 F/4-5.6 III?

The Canon teleconverters are only compatible with a select number of Canon’s pro level telephoto lenses.  Unfortunately, the 2X III Extender is not compatible with the EF 75-300mm lens.

Can I use 2X III canon extender with Canon 28-300L lens on Canon 50D body?

Unfortunately, the Canon Extender EF 2X III is not compatible for use with the Canon EF 28-300mm f/3.5-5.6L IS USM Lens.


Can I use a x1.4 Canon extender on an EF 40mm f/5.6L lens?



The Canon extenders are only compatible with a select number of Canon’s pro-level telephoto lenses.  They would not be compatible with a 40mm lens.  Now, if you are referring to the 400mm f/5.6 lens, you can use that lens with the 1.4X III extender.  Do keep in mind, though, that unless you have a 1D series camera or the 5D III with the most recent firmware, autofocus will not be retained; on all other cameras the lens will need to be manually focused when used with an extender.

The 80D will autofocus with the 1.4x III extender.

Hi ,I am using Cnon 80D with Canon 400mm,f5.6L,USM,can I get autofocus with 1.4x III extender?

Expect your precious comment.



Autofocus can be retained when using the Canon 1.4X III extender with the 400mm f/5.6 on the 80D, yes.  The 80D’s AF system is capable of retaining autofocus with lenses that have a max aperture of at least f/8, which would be the new effective aperture of the 400mm f/5.6 when used with a 1.4X extender.  At this time Canon's 1D series of cameras, 5D III, 5DS/5DS R, 7D II, and 80D are all capable of AF at f/8.