The Canon RF 14-35mm F4 L IS USM ($1,699) is an exceptionally lightweight zoom lens, especially when you realize it's made for full-frame sensor cameras and enables an ultra-wide angle of view. It's not a surprising design choice; many of Canon's RF lenses prioritize portability. The 14-35 F4 has more optical compromises than you might expect from an L series lens, but you may forgive those flaws because of how compact it is. We still recommend the RF 15-35mm F2.8 L IS USM ($2,399) for more critical and technical work, but the RF 14-35mm is a better fit for those who want to pack light.

A Zoom You'll Take With You

Ultra-wide lenses are useful tools for capturing wide landscapes or exploring the tight spaces of the urban world, but they're not always the easiest to carry. Canon takes a page out of rival Nikon's playbook here and delivers an ultra-wide zoom that you'll want to take with you. The RF 14-35mm measures 3.9 by 3.3 inches (HD) and weighs just 1.2 pounds, not far off from the Nikkor Z 14-30mm F4 S for the Nikon Z system (3.4 by 3.5 inches and 1.1 pounds).

The RF 14-35mm F4 takes up less room in your bag than the other wide zoom for Canon's EOS R system; the 15-35mm F2.8 measures 5.0 by 3.5 inches and weighs 1.9 pounds. Major third-party lens manufacturers haven't jumped on to support the system yet, so you're limited to Canon's lenses unless you reach for the EF-EOS R adapter. We haven't reviewed the Tokina atx-i 17-35mm F4 ($599) for Canon SLRs, but it's one to consider if you're on a budget.

The RF 14-35mm is part of Canon's L series, the designation for its highest class of lenses. Like other L lenses, it features dust and splash protection and is suitable for use outdoors even when the weather gets a little rough. The front element benefits from an anti-smudge fluorine coating and is flat enough to support 77mm threaded filters.

The ultra-wide's petal-style lens hood has a push-button lock. Aside from the hood, the lens ships with a pinch-style lens cap, a standard rear cap, and a soft drawstring pouch.

Handling and Autofocus

The RF 14-35mm includes three on-barrel control rings and a pair of toggle switches: one swaps focus modes and the other turns stabilization on or off. The zoom ring is the largest of the three rings and sits closest to the lens mount. It sports rubber ridges and is tapered, with its diameter at the front slightly larger than at the rear. This design touch is thoughtful and goes a long way to prevent you from tapping the manual focus ring that sits just in front of it.

Autofocus is quiet and quick, while manual focus behavior is pleasant. Vloggers and snapshooters will be content to let the camera drive focus, but for more serious video work, manual focus is still preferable. The RF 14-35mm supports both linear and nonlinear focus response; the focus control direction is reversible, too. Focus breathing is well controlled and there's no apparent change in angle when setting focus. It's a strong option for video, either with an EOS R mirrorless camera or Canon's RF-mount EOS C70 cinema camera.

You can set the function of the third control ring that sits at the front of the barrel via the camera menu. I find it useful for direct EV adjustments, but your mileage may vary. The ring clicks when you turn it, which is helpful for making discrete adjustments to settings, but that behavior may be distracting if you're recording in-camera audio. Canon can de-click the ring for a reasonable $79.99 fee. It's one area where Canon can improve, however—many lens makers, including rival Sony, include a toggle to click or de-click control rings right on the barrel of some lenses.

Like most wide-angle zooms, the RF 14-35mm focuses close, as near as 7.9 inches from the camera's sensor. At wide angles, it can draw small subjects with big swaths of background, and at 35mm, it nets 1:2.6 life-size reproductions. That's not far behind the dedicated $499 RF 35mm F1.8 Macro IS STM (1:2).

The 14-35mm includes optical stabilization as well, effective to 5.5 stops when using a camera with a fixed sensor, such as the first-generation EOS R and entry-level EOS RP, or 7 stops when you attach it to a camera with a 5-axis IBIS sensor, such as the EOS R3, R5, and R6. I tested the lens with the EOS R5 and enjoyed blur-free handheld exposures at durations of up to 1.6 seconds when focusing on subjects a few feet away. The stabilization isn't as effective at near distances, though, so I was limited to a shutter speed of 1/4-second when focusing as close as possible.

RF 14-35mm L in the Lab

I paired the RF 14-35mm with the 45MP Canon EOS R5 and Imatest software to check its optical performance. At 14mm and f/4, it shows its weakest lab results; it's excellent near the center of the frame (4,200 lines), but soft toward the edges. Narrowing the aperture to f/5.6, f/8, or f/11 (settings that are better for traditional landscape work anyway), sharpens results in the center (4,500 lines) and nets more detail at the edges. Images shot at f/16 and f/22 aren't as crisp, a result of diffraction, an effect that causes light to scatter as it passes through a very small aperture.

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Sharpness is more consistent from center to edge when the lens is set to a longer focal length. We tested it at 25mm and 35mm. It produced excellent results at f/4 (4,100 lines), as well as stopped down to f/5.6 and f/8 (4,300 lines).

The 14-35mm's struggles at 14mm are tied to the optical corrections required to compensate for its heavy barrel distortion and optics that don't quite cover the entire full-frame sensor—corners are black. If you're using your camera for JPG capture or video, you won't see this issue because the image processing engine applies distortion and vignette corrections automatically. Those fixes come with a cost—the angle of view is a little tighter after correction. The difference is easy to see in the comparison above between a Raw and JPG capture at the same exposure.

Raw photographers are in more of a pickle. If you use Adobe Lightroom Classic for processing, you have access to a custom-made correction profile. You can set it to apply automatically when importing images into your catalog, or click it on and off—it's perfectly effective, straightening out curved lines and knocking out the vignette. But these fixes aren't as easy if your software doesn't supply a correction profile. Lightroom's biggest rival, for example, Capture One Pro, has been slow to add profiles for Canon RF lenses. At press time, that software offers profiles only for the first batch of Canon's RF lenses from 2018.

Wide lenses are a good fit for landscape work and getting sharp multi-point sunstars is an oft-desired look for the genre. The RF 14-35mm does a good job delivering that effect at its smallest apertures, netting 18-point sunbursts with crisply defined edges at f/16 and f/22.

At wider apertures, you can easily blur out backgrounds, especially when working up close and toward the long end of the zoom range. Defocused highlights are mostly circular, while those at the edges of the frame show a slight cat's eye effect at f/4. Rounded aperture blades draw them as circles when set to f/5.6 and smaller settings.

Corrections Aren't Quite Transparent

Canon succeeded in making the RF 14-35mm F4 L IS USM appealing for photographers who prefer to carry a lighter kit. It's nearly half the weight as the other wide zoom for the system, the RF 15-35mm F2.8 L IS USM, and still includes optical stabilization. It might be a stretch for photographers who bought into the system with the affordable EOS RP, but it's a good match for the camera otherwise.

If you can't manage the $1,699 price, consider the $299 RF 16mm F2.8 STM as an alternative—it's not built to L series standards, but that's hard to complain about given the cost. We'd love to see Canon release a more affordable RF zoom to cover ultra-wide angles.

For photographers less sensitive to price, the RF 14-35mm lives up to its L series bonafides in terms of its fit and finish. The lens is every bit as well made as the RF 15-35mm F2.8. However, we're rating the RF 14-35mm a little lower than that ultra-wide, because images taken at the wide end with this lens require corrections in many cases—we don't mind optical corrections when they're invisible, but that's not the case here. Still, the lens represents a reasonable compromise for traveling shutterbugs who prefer to take Raw photos (and don't mind the extra work) or who primarily shoot JPGs and video.