Canon RF vs EF lenses: five key reasons to upgrade

The steadily growing Canon RF lens range gives photographers and hybrid shooters more options than ever before. However, you may be more familiar with Canon's well-established EF lenses, which have been proven in the field over many years. So, what is the difference between Canon EF and RF lenses – and should you choose an EF or an RF lens when you get an EOS R System camera?

At the heart of Canon's mirrorless EOS R System, the innovative RF mount has enabled a new generation of optical technology, giving users new creative possibilities. For example, the range of Canon RF lenses includes the RF 85mm F1.2L USM DS, the first lens with Canon's unique Defocus Smoothing coating, which delivers unprecedented smooth bokeh in out-of-focus areas. The RF mount also supports groundbreaking Canon 3D/VR lenses for creating immersive content, and hybrid lenses that offer uncompromising performance for both video and stills.

If you’re weighing up whether you should go all-in with RF primes and zooms when you move to mirrorless, or if you’re already there and still using EF lenses via a mount adapter, this guide to Canon EF versus RF lenses highlights five reasons why there’s never been a better time to upgrade.

1. New lens capabilities

2. Size and weight savings

3. Better quality glass

4. Greater choice of focal lengths

5. New concept lenses

"The Canon RF lens range is not designed to replicate what's available in EF, but to bring something new to the table," says John Maurice, European Product Marketing Manager at Canon Europe. "Take, for example, Canon's 'f/2.8 trinity' of RF zooms" – three RF lenses covering ultra-wide, standard and telephoto zoom ranges, which together deliver the entire focal length range that working photographers need to shoot in practically any situation. All three have Image Stabilizers, including the RF 15-35mm F2.8L IS USM and RF 24-70mm F2.8L IS USM, where the corresponding EF lenses do not.

The high speed at which the camera and lens communicate with each other across the RF mount has enabled lens designers to introduce new lens capabilities that haven’t been possible before. For example, many RF lenses have a dedicated Control Ring that provides an intuitive and rapid way to adjust key camera settings such as the aperture or AF area. Canon hybrid RF lenses have an additional Iris Ring for smooth and silent aperture change while recording video.

The aperture mechanism in an RF lens can be adjusted more quickly and in smaller increments of 1/8 stop, compared to standard 1/3 stop increments in EF lens designs. This is beneficial when you're shooting video, where you don’t want sudden jumps in brightness.

Another advantage of upgrading from EF to RF lenses when you move to a mirrorless EOS R System camera is the size and weight savings that can be made. Although it is possible to continue using your EF and EF-S lenses via a mount adapter, the adapter itself will add at least 110g to the combined camera body and EF lens weight. The whole setup will be more front heavy too, as the larger front elements of the lens will be further away from the camera body.

Many RF lenses are smaller and lighter than their EF counterparts. The Canon RF 24-105mm F4L IS USM weighs 700g, for example, while its EF equivalent comes in almost 100g heavier, at 795g. The Canon RF 10-20mm F4L IS STM (570g) is over 50% lighter than the Canon EF 11-24mm f/4L USM (1,180g), plus it's shorter, goes wider and is equipped with an Image Stabilizer too.

Wide-angle and fast-aperture lenses benefit the most from the design of the RF mount, but telephoto lenses are typically more streamlined too. "The third lens in the Canon RF f/2.8 trinity, the RF 70-200mm F2.8L IS USM, is much smaller and lighter than its EF counterpart," John notes. "Photographers expect a 70-200mm f/2.8 lens to be heavy, but it’s really not, and the sharpness of this lens is amazing."

Joel points out: "The Canon RF 70-200mm F2.8L IS USM is about a third lighter than the equivalent EF lens. It's very short when it's retracted, so it's very practical for packing, plus it attracts less attention when you are walking around, which is important for my style of photography." Combined with the more compact Canon EOS R System bodies, this means RF lenses are a great choice for travel photography, as well as wildlife, street photography and other genres where light weight and portability are critical.

Joel adds: "My main concern when travelling – especially with airline restrictions – is how to reduce weight and bulk without compromising performance or a goal I need to accomplish. On a trip to cover the Voodoo Festival in Benin, for example, I could only take my main lenses – a Canon RF 15-35mm F2.8L IS USM, an RF 24-70mm F2.8L IS USM and an RF 70-200mm F2.8L IS USM. But the fact that these lenses are so compact meant I could have two bodies with lenses mounted inside my bag, ready to go."

Canon EOS R System cameras carry lens maps for every EF lens, so they are able correct for lens aberrations such as diffraction and chromatic aberration in a highly efficient way. However, native RF lenses provide a step up in image quality. The design of the RF mount means that the large diameter lens elements can be positioned at the rear of the lens, closer to the camera’s imaging sensor. Light rays don't have to bend as much as they pass through the lens, making it possible to offer wider maximum apertures and achieve better image quality from corner to corner.

The enhanced communication between an RF lens and an EOS R System camera means that lens aberrations can be corrected at high speed using DLO processing, further improving image quality. There’s no reduction in performance either, which is why the Canon EOS R1 can execute this process 40 times a second. Digital correction is an integral part of the design of modern RF lenses. Advanced electronic corrections of distortions and aberrations can be factored in right from the start, giving engineers the flexibility to focus on optimising sharpness, contrast and size efficiency in their optical design.

The improvements in optical technology and digital processing mean that today’s RF lenses are able to outperform their EF counterparts in many situations. With two aspherical elements and four UD, plus a fast f/2.8 maximum aperture throughout its zoom range, the Canon RF 16-28mm F2.8 IS STM offers all the image quality you’d have expected from an L-series EF lens. The RF 24mm F1.8 MACRO IS STM is capable of delivering better image quality than the EF 24mm f/1.4L II USM – in a small, lightweight lens that is also equipped with an Image Stabilizer, 0.5x macro capability as close as 14cm from a subject, and customisable Lens Control Ring that allows fine tuning of ISO, aperture or AF method as well as a dedicated focus ring for precise manual focusing.

"The Canon RF 28-70mm F2L USM is a game-changing lens for me,” Joel says. “I see it as a pack of f/2 primes – a 28mm, a 35mm, a 50mm and a 70mm – in a single zoom. If you add up the weight of all these separate prime lenses, and the time you'd spend swapping between them – not to mention the money you'd have to spend – you can see what a practical option it is.

"I was shooting a documentary in Niger during a sandstorm, so I couldn't risk swapping lenses – and one lens did it all. I ended up doing all my photography and video work almost exclusively on the RF 28-70mm F2L USM. For me, this lens alone justifies swapping to the RF system."

Now that the RF lens family has matured, it offers a more expansive range of focal lengths than the EF lens line-up. The current RF lens range runs from 3.9mm to 1,200mm and can be extended up to 2,400mm with the use of RF extenders.

Lightweight, ultra-wide-angle lenses such as the Canon RF 10-20mm F4L IS STM (the world’s widest-angle AF zoom lens¹) and the ultra-pocketable RF 16mm F2.8 STM are giving photographers new levels of creative freedom, while dual lenses such as the RF 5.2mm F2.8L DUAL FISHEYE enable content creators to explore the world of 180-degree VR filmmaking.

EOS R System cameras are capable of focusing at smaller maximum apertures than EOS DSLRs, which has opened the door to revolutionary super-telephoto lens designs that haven’t been practical or possible before. Lenses such as the Canon RF 1200mm F8L IS USM and RF 800mm F11 IS STM are incredibly lightweight and provide responsive autofocus even when paired with a 2x RF Extender (where the maximum apertures are reduced to f/16 and f/22 respectively).

It isn’t just gains in performance and portability that the RF lens range offers, but the opportunity to use groundbreaking new lens designs that have never been available in the EF mount.

Take the EOS VR System, for example. This complete solution for creating immersive 3D and virtual reality content using selected EOS R System cameras includes Canon’s stereoscopic and VR lenses. These innovative optics let you capture the world in epic new ways and record two images simultaneously on a single camera sensor for a smoother shooting and post production workflow.

And while RF lenses are designed with both stills and video in mind, hybrid RF lenses offer enhanced filmmaking capabilities in addition to outstanding performance for photography. Video-optimised features include an Iris Ring that can be used for even smaller manual adjustments of the aperture in 1/32 steps when recording movie footage, minimal focus breathing, and the option of using Canon Power Zoom adapters for greater control with RF hybrid zoom lenses.

Interested in a particular genre? Take a look at this expert advice on the best lenses for landscapes, best lenses for portraits, best lenses for macro photography, best RF lenses for video and best cameras and lenses for wildlife photography. You can explore the full range of Canon RF lenses using the Canon lens selector, which will help you find the perfect match for your EOS R System camera and your preferred genre of photography.