Canon RF 14-35mm f/4 L IS USM lens
While the RF 14-35mm f/4 L IS USM lens is a stop slower than its main rival, it’s also considerably smaller, lighter, more affordable and covers a wider angle of view.
The superior performance of today’s cameras makes faster lenses less necessary for low-light work, while few users will find substantial differences in depth of focus at the widest angles of view.
Announced at the end of June 2021, the Canon RF 14-35mm f/4 L IS USM lens has the widest angle of view of the current RF lens range. Smaller, lighter, closer-focusing and less expensive than the one-stop faster RF 15-35mm f/2.8L IS, the RF 14-35mm lens has better image stabilisation (IS) with up to 5.5 stops of shake correction, compared with five stops in the 15-35mm lens. The RF 14-35mm lens is also lighter and shorter than the EF 16-35mm f/4L IS USM, its closest DSLR equivalent (which we haven’t reviewed).
Angled view of the RF 14-35mm f/4L IS USM lens with the supplied lens hood fitted. (Source: Canon.)
All three lenses come with rounded, nine-bladed iris diaphragms that ensure attractive bokeh. They also have similar ultrasonic motor-driven autofocusing systems. But the new RF 14-35mm lens can focus down to 20 cm at 35mm, while the EF 16-35mm and RF 15-35mm f/2.8L IS lenses are limited to 28mm.
This diagram shows the positions of the exotic elements in the optical design of the RF 14-35mm f/4L IS USM lens.
The optical design of RF 14-35mm f/4 L IS USM lens contains 16 elements in 12 groups and includes two ultra-low dispersion (UD) elements and two glass-moulded (GMo) aspherical elements plus one element that is both UD and aspherical. The lens is also multi-coated, with Sub-wavelength Structure Coating, Super Spectra Coating and Air Sphere coating plus a fluorine coating on front element to repel moisture, grease and dust and make it easy to keep clean.
The table below shows the main differences between the RF 14-35mm f/4 L IS USM and RF 15-35mm f/2.8L IS lenses.
|RF 14-35mm f/4 L IS USM
|RF 15-35mm f/2.8L IS
|104 to 54 degrees horizontal
|110 degrees 30 minutes to 63 degrees
|16 elements in 12 groups
|3 UD elements and 3 GMo aspherical elements with 1 element both UD & Aspherical
|3 GMo aspherical and 2 UD elements
|SWC, ASC and fluorine
|Dimensions (Diameter x L)
|84.1 x 99.8 mm
|88.5 x 126.8 mm
|Front and end caps, EW-83P lens hood, LP-1219 lens pouch
|Front and end caps, EW-88F lens hood, LP-1222 lens pouch
|RRP on release
|Average street price Jan. 2022
Who’s it For?
Since Canon has yet to release a cropped-sensor camera with the RF mount, the 14-35mm lens can only be used on Canon’s ‘full frame’ cameras. While its wide-angle coverage at 14mm is the greatest so far in the RF mount lens range, zooming extends it to the same 35mm end of the scale as the 15-35mm lens.
Its wider coverage angle, lighter weight and smaller size will make the 14-35mm lens more versatile than the 15-35mm lens. Although a stop slower, it is equally suitable for photographing subjects as diverse as landscapes, night skies and architecture (including real estate shots), extending through to group portraits and street scenes.
Applications in the field of portraiture are limited for both lenses due to the inherent distortions with ultra-wide angles of view. The 35mm focal length is fine for full-body portraits and shots of small groups (two or three subjects) but the best portraiture applications for both lenses are environmental portraits and shots showing people in a larger scene.
Although ultra-wide angle lenses usually have limited close-up capabilities, the Canon RF 14-35mm lens can focus to within 20 cm of subjects where it comes close to one third life-size reproduction with the 35mm position. This makes it slightly more useful than the faster lens for close-ups as background blurring is similar with both lenses.
The quiet ultrasonic AF drive will allow videographers to take advantage of the versatility of this lens. They will also benefit from the smooth controls, minimal focus breathing and up to seven stops of shake correction available when the lens is fitted to one of the newer camera bodies that include IBIS.
Build and Ergonomics
Most of the basic structure of this lens is made from magnesium alloy, with a similar external cladding of high-quality polycarbonate to the 15-35mm lens giving it an attractive look and feel. There are similar weather-resistant seals around the lens mount, switches, zoom ring, focus ring and control ring, as shown in the diagram below.
This diagram shows the extensive weather-resistant sealing in the RF 14-35mm f/4 L IS USM lens. (Source: Canon.)
Focusing is totally internal and the inner barrel is shortest with the lens set between the 20mm and 26mm focal lengths. It extends by roughly 10mm when the lens is zoomed to the 14mm position and again at the 35mm position. A 5mm wide section at the front of inner barrel carries a bayonet mounting for the shallow, petal-shaped lens hood, which has a locking button and can be reversed for transport or storage.
Just behind the red Canon branding ring and approximately 5mm back from the leading edge of the outer barrel is the programmable control ring. It’s roughly 10mm wide and has is textured to make it easily identifiable by touch.
The control ring can be programmed via C-Fn III-6 in the camera’s Custom menu to adjust one of a range of exposure settings, including aperture, ISO and exposure compensation. By default, it has click stops to enable users to control how much it is being turned. (It can be de-clicked by the Canon Service Centre – for a fee – if silent operation is required.)
A 5mm wide band separates the control ring from the focusing ring, which is 14mm wide and almost completely clad with fine ridges to provide a secure grip. Since focusing is driven from the camera, this ring turns through 360 degrees when power is switched off.
The zoom ring is located immediately behind the focusing ring. It’s roughly 26mm wide with noticeably thicker ridges than the focusing ring and slopes inwards about half way along its length. A 3mm wide un-ridged band on the trailing edge of the zoom ring is stamped with focal length marks for the 14mm, 20mm, 24mm, 28mm and 35mm settings.
Behind the zoom ring is an un-ridged section of the barrel that is approximately 22mm wide. Slider switches for the focus mode (AF/MF) and image stabiliser (ON/OFF) are located around the left hand side of this section of the barrel.
The lens barrel then steps in to the metal lens mount, which has a red index mark on its outer surface for mounting the lens plus a rubber ring to keep out moisture and dust. Inside the mount are 12 gold-plated contact points for exchanging signals between the lens and the camera.
We tested the RF 14-35mm f/4 L IS USM lens on an EOS R6 camera body for which it was an excellent match – both size- and performance-wise. Our Imatest tests showed the camera and lens combination to be capable of comfortably exceeding expectations with measurements from the centre of JPEG images as well as meeting expectations for measurements taken half-way out from the centre.
Measurements taken towards the periphery of the frame fell a little short of expectations, as we’d anticipated for such a wide angle lens. With raw files, which were converted in to 16-bit TIFF format with Adobe Camera Raw, resolution comfortably exceeded expectations across most of the frame, falling only marginally short near the periphery.
The best performance was recorded with the 35mm focal length at f/5.0. Diffraction began to take effect between f/8 and f/11 with all focal length settings, as shown in the graph of our test results below.
Lateral chromatic aberration measurements were taken with all in-camera corrections disabled, since this flaw is normally corrected by default in JPEG files. In our tests it remained within the ‘negligible’ band The graph below shows the results of our tests on JPEG files, with the red line marking the border between ‘negligible’ and ‘low’ CA.
Interestingly, test shots captured in the CR3.RAW format showed visible coloured fringing towards the edges of the frame when no optical corrections were applied. Examples can be found in the Samples section of this review.
Because rectilinear distortion and vignetting are corrected by default in JPEG files in EOS cameras, we disabled them for these tests and also used CR3.RAW files to measure both aberrations. Barrel distortion was visible at the 14mm and 20mm focal lengths but at 28mm the lens was essentially distortion-free. Slight pincushion distortion appeared at the 35mm focal length.
Vignetting could be seen at f/4 with all focal lengths, which was expected for this type of lens. It was slightly more obvious at 14mm and 20mm but also quite visible at 35mm. Stopping down to between f/5 and f/5.6 largely eliminated it and it is easily corrected with in-camera corrections and when converting raw files into editable formats.
On the whole, backlit subjects were handled well, with little in the way of flare artefacts when a bright light source was just within or just outside of the frame, especially with wider angles of view. We found no apparent loss of contrast due to veiling flare.
Sunstars were difficult to attempt because of the all-encompassing angles of view this lens provides. Nonetheless, we managed to obtain some acceptable ones with both 14mm and the 35mm focal length and the nine-bladed iris diaphragm produced 18 pointed stars.
Autofocusing was generally fast and accurate and the built-in stabilisation system enabled us to capture blur-free test shots with shutter speeds as slow as half a second in dim lighting. Close focusing is limited to 20 centimetres throughout the zoom range, where it provides a maximum magnification of 0.15x at 14mm ranging through to 0.38x at 35mm.
Bokeh was much as you would expect for an ultra-wide angle zoom lens. At f/4, out-of-focus backgrounds at 14mm were a little softer than we’d expected but still somewhat choppy. Highlights took on an oval shape towards the edges of the frame. By 35mm, an acceptable degree of background softening was possible and the 20 mm minimum focus made it easier to fill the frame with the subject.
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Picture angle: 104 to 54 degrees horizontal (114-63 degrees diagonal)
Minimum aperture: f/22
Lens construction: 16 elements in 12 groups (including 3 UD elements and 3 GMo aspherical elements with 1 element both UD & Aspherical), Sub-wavelength Structure Coating, Super Spectra Coating and Air Sphere coating plus fluorine coating on front element
Lens mounts: Canon RF
Diaphragm Blades: 9 (circular aperture)
Weather resistance: Weather-resistant seals around lens mount, switches, zoom ring, focus ring and control ring
Focus drive: Nano USM rear focusing system
Stabilisation: Yes, up to 5.5 stops (CIPA)’ 7 stops with Image Stabilizer IBIS + OIS
Minimum focus: 20 cm
Maximum magnification: 0.15x at 14mm to 0.38x at 35mm
Filter size: 77 mm
Dimensions (Diameter x L): 84.1 x 99.8 mm
Weight: 540 grams
Standard Accessories: Front and end caps, EW-83P lens hood. LP-1219 lens pouch
Distributor: Canon Australia; 1800 021 167
Based on JPEG files taken with the Canon EOS R6 camera.
Based on CR3.RAW files converted into 16-bit TIFF format with Adobe Camera Raw.
Vignetting at 14mm, f/4.
Vignetting at 20mm, f/4.
Vignetting at 24mm, f/4.
Vignetting at 28mm, f/4.
Vignetting at 35mm, f/4.
Rectilinear distortion at 14mm.
Rectilinear distortion at 20mm.
Rectilinear distortion at 24mm.
Rectilinear distortion at 28mm.
Rectilinear distortion at 35mm.
14mm focal length, ISO 200, 1/160 second at f/10.
20mm focal length, ISO 200, 1/200 second at f/10.
24mm focal length, ISO 200, 1/250 second at f/10.
28mm focal length, ISO 200, 1/250 second at f/10.
35mm focal length, ISO 200, 1/250 second at f/10.
Close-up at 14mm focal length, f/4, ISO 200, 1/1600 second.
Close-up at 20mm focal length, f/4, ISO 200, 1/1600 second.
Close-up at 24mm focal length, f/4, ISO 200, 1/1250 second.
Close-up at 28mm focal length, f/4, ISO 200, 1/1600 second.
Close-up at 35mm focal length, f/4, ISO 200, 1/1600 second.
Close-up at 14mm focal length, ISO 200, 1/60 second at f/6.3
Close-up at 35mm focal length, ISO 200, 1/100 second at f/6.3.
14mm focal length; ISO 200, 1/60 second at f/10.
Crop from the edge of the above image magnified to 100% showing coloured fringing.
35mm focal length, ISO 200, 1/80 second at f/10.
Crop from the edge of the above image magnified to 100% showing coloured fringing.
Handheld shot, 14mm focal length; ISO 200, 1/6 second at f/6.3.
Handheld shot, 35mm focal length, ISO 200, 1/2 second at f/4.
Sunstar at 14mm focal length, ISO 200, 1/60 second at f/22.
Sunstar at 35mm focal length, ISO 200, 1/50 second at f/22.
14mm focal length, ISO 400, 1/20 second at f/8.
14mm focal length, ISO 200, 1/640 second at f/4.
35mm focal length, ISO 200, 1/200 second at f/8.
14mm focal length, ISO 200, 1/320 second at f/7.1.
26mm focal length, ISO 200, 1/100 second at f/6.3.
14mm focal length, ISO 200, 1/6 second at f/9.
14mm focal length, ISO 200, 1/320 second at f/9.
14mm focal length, ISO 200, 1/640 second at f/9.
RRP: AU$2999; US$1699
- Build: 9.0
- Handling: 8.9
- Image quality: 9.0
- Autofocusing: 9.0
- Versatility: 8.9