Canon RF 100-400mm f/5.6-8 IS USM review

A compact and affordable super-telephoto zoom for Canon EOS R-series cameras

Canon RF 100-400mm f/5.6-8 IS USM
(Image: © Future)

Digital Camera World Verdict

Compact and lightweight for a super-telephoto zoom, the Canon RF 100-400mm f/5.6-8 IS USM looks and feels very much like shooting with a classic 70-300mm lens on an APS-C format camera. Naturally though, it’s designed for EOS R-series full-frame bodies, on which it’s an excellent fit, making for a slimline and easily manageable overall package. Autofocus is super-fast, image stabilization is highly effective and image quality is highly impressive in all respects, with the caveat that sharpness drops off noticeably when combining close focusing distances with the longest zoom setting. The aperture rating of f/8 at the long end of the zoom range might be a bit slower than some might like, but that’s the price you pay for the conveniently downsized design.


  • +

    Powerful super-telephoto zoom range

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    Refreshingly compact and lightweight

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    5.5-stop optical image stabilizer


  • -

    Fairly slow f/5.6-8 aperture rating

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    ‘Optional’ lens hood is a pricey extra

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    No weather-seals

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The sheer number of Canon RF-mount super-telephoto lenses puts Nikon to shame. The RF 100-400mm joins a powerful yet easily manageable pair of RF 600mm F11 IS STM and RF 800mm F11 IS STM primes, along with the more pro-spec Canon RF 100-500mm f/4.5-7.1 IS USM zoom lens. Canon also has a pair of heavy-duty RF 400mm F2.8L IS USM and RF 600mm F4L IS USM on its books, at a time when the Z 100-400mm f/4.5-5.6 S is the solitary Nikon Z-mount super-tele on the market.

Ultimately, the RF 100-400mm is ideally suited to mirrorless shooting, being impressively compact and weighing just 635g, despite its powerful maximum reach. However, with an aperture gearbox that only shifts between f/5.6 and f/8, can this lens really deliver for the sports, wildlife and all-purpose shooters at whom its aimed?

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Dan Mold
Deputy Editor

Deputy Editor on PhotoPlus: The Canon Magazine, Dan also brings his technical wizardry and editing skills to Digital Camera World. He has been writing about all aspects of photography for over 10 years, having previously served as technical writer and technical editor for Practical Photography magazine, as well as Photoshop editor on Digital Photo

Dan is an Adobe-certified Photoshop guru, making him officially a beast at post-processing – so he’s the perfect person to share tips and tricks both in-camera and in post. Able to shoot all genres, Dan provides news, techniques and tutorials on everything from portraits and landscapes to macro and wildlife, helping photographers get the most out of their cameras, lenses, filters, lighting, tripods, and, of course, editing software.