Canon Extender RF 1.4x review: a revamped teleconverter for the EOS R-system

The Canon Extender RF 1.4x is a teleconverter designed from the ground up for Canon’s EOS R-system mirrorless cameras and select telephoto lenses.

Canon Extender RF 1.4x
(Image: © Matthew Richards)

Digital Camera World Verdict

I’m a fan of the quality and performance of the Canon Extender RF 1.4x, which makes it well worth the price. I just wish it was compatible with more of Canon’s L-series telephoto lenses.


  • +

    Excellent performance

  • +

    Tough, weather-sealed construction

  • +

    1.4x boost in telephoto reach


  • -

    Limited compatibility list

  • -

    Pretty pricey for a 1.4x teleconverter

  • -

    The usual 1 f/stop aperture reduction

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The Canon Extender RF 1.4x is designed for EOS R-system mirrorless Canon cameras and compatible RF-mount Canon telephoto lenses. As such, it builds on the strength and reputation of the latest Canon Extender EF 1.4x III for DSLRs, which can also be used on EOS R cameras via an EF-EOS R mount adapter. Aimed at professional and enthusiast photographers, it sets out to be one of the world’s best teleconverters

Even with its front and rear caps fitted, the Canon Extender RF 1.4x is small enough to slip into a coat pocket. (Image credit: Matthew Richards)
Swipe to scroll horizontally
MountCanon RF
Lens construction7 elements in 4 groups
Focal length multiplier1.4x that of main lens
Aperture reduction1 f/stop
Minimum focus distanceSame as main lens
Maximum magnification1.4x that of main lens
Dimensions71.2 x 20.3mm
Canon Extender RF 2x

The Canon Extender RF 2x gives you double the telephoto boost instead of 1.4x, but with two f/stops of aperture reduction instead of just one f/stop.


If you’re using Canon EF-mount telephoto lenses on a DSLR or an EOS-R camera via a mount adapter, buy the Canon Extender EF 1.4x III instead.

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Matthew Richards

Matthew Richards is a photographer and journalist who has spent years using and reviewing all manner of photo gear. He is Digital Camera World's principal lens reviewer – and has tested more primes and zooms than most people have had hot dinners! 

His expertise with equipment doesn’t end there, though. He is also an encyclopedia  when it comes to all manner of cameras, camera holsters and bags, flashguns, tripods and heads, printers, papers and inks, and just about anything imaging-related. 

In an earlier life he was a broadcast engineer at the BBC, as well as a former editor of PC Guide.