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EOS forum round-up

The forum is the perfect place to find out more about a piece of kit before purchasing it. If you are unable to borrow before you buy, what better way to find out about your intended purchase than asking for feedback?

Member mikita wanted to extend the reach of his EF 70-200mm lens by using it with an Extender (Canon uses the name Extender rather than teleconverter, which is the more universal term):

“I am contemplating buying the 2x converter for use with my EF 70-200mm f2.8L IS II USM lens and EOS 5D Mark III. I am interested to know what experiences other users have had with the converter, especially regarding the effect on aperture. At present I use a Sigma 100-500mm for reach, but am happy to lose a bit of reach to have the quality of Canon. I will appreciate any feedback please."

Farider was the first to reply: “I can’t help with the 2x, but I do have the 1.4x and that works very well with my EF 100-400mm. You lose 1 stop on the 1.4x and 2 stops, I believe, on the 2x. Any loss in quality for the 1.4x is insignificant.

Farider is correct. When you attach an Extender 1.4x it reduces the lens aperture by 1 stop. So on mikita’s lens, the maximum aperture of f2.8 is reduced to f4. The Extender 2x reduces the lens aperture by 2 stops so, on the same lens, the maximum aperture is reduced further to f5.6. Crucially, depending on your camera and lens combination, this can have an impact on autofocusing capabilities. All EOS cameras can autofocus down to a maximum aperture of f5.6, so with mikita’s kit the autofocusing is unaffected.

“I use the 1.4x both on the EF 100-400mm and EF 70-200mm, and have no problems,” says Trev B. “A friend of mine has got a 2x. I’ve used it, but was not impressed. You lose 2 stops. He finds that with his 1.4x he’s OK hand-holding, but with the 2x it’s a bit of a problem.”

colin C (Colin Cross) shares his experience of using both Extenders: “I have both Extenders and am happy to use the 1.4x anytime and on any of my compatible telephoto lenses. The 2x I am a bit more cautious with. I have had some terrible results, but in fairness that was in terrible conditions where I was fighting for some light and using it was almost an act of desperation. In good light and the right conditions the Mark III version can deliver some very good results, but you need to give a fair crack of the whip.

“Although I have plenty of rubbish shots with the Extender 2x, this image (above) was taken at ISO 3200, manually focused, on an 800mm lens with an Extender 2x, giving a total of 1600mm and f11. Struggling a bit for light and having no autofocus available I didn’t expect much and was rather surprised how well it came out.”

“So it just goes to show the 2x in the hands of an expert is a nice bit of kit,” says Trev B.

Kingfisher image captured by Colin Cross. Using an Extender 2x with his particular camera and lens combination means that autofocus is lost, but Colin Cross still managed an impressive shot using manual focus. EOS-1D X Mark II, EF 800mm f5.6L IS USM lens with Extender EF 2x Mark III at 1600mm, 1/400 second, f20, ISO 3200.

Extenders

For further information on using Extenders, and which Canon lenses are compatible, turn to our article ‘Extender update’, January-March 2020, pages 60-65.

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