Canon is slowly rolling out camera lenses that are native to their EOS R and RP formats. Three of these are the most commonly used zoom lenses, covering 70-200m, 24-70mm and the one we will be looking at today, the Canon RF 15-35mm f/2.8L IS USM. It’s immediately apparent that these lenses are for the next generation of camera bodies and should have the latest and greatest set of features.
These lenses have lots of potential with the build quality you would expect from the L series. But, with such high price tags, are these lenses the best options and are these the best Canon lenses currently available?
A simple external design is the way forward for these new lenses. The Canon RF 15-35mm f/2.8L IS USM follows the same lines as the other offerings, showing just the external rings and two switches as external controls. It’s also reassuringly heavy at 840g, which means there’s a lot of glass inside this thing. Not so much a problem on a regular DSLR body, but on a lighter weight EOS R body, the lens can feel front heavy, unless you’re using the optional battery grip.
The lens has the L-series build quality, which means it’s weatherproofed and is made from a rock-solid metal construction. L-series lenses, denoted by the thin red line around the lens, doesn’t just mean the best build and optics, but it’s designed for the working photographer. Thus, the 15-35mm should be the new standard from which others are measured in the line.
It may seem initially strange to not have things like a distance scale on the lens. However, this functionality has been moved in-camera which allows for a third ring on the lens, which we will come onto next.
The exterior of the Canon RF 15-35mm f/2.8L IS USM consists of three different width rings. The one closest to the camera body and is the largest, is the zoom ring which has a rubberized, ridged feel for extra grip. Focal lengths are printed under the ring, which go from 20mm, 24mm, 28mm, and 35mm. Next along is the manual focusing ring, which has a slightly different feel, having closer ridges and just enough resistance to feel your way around.
The ring nearest the front of the lens has a knurled feel and can be customized to change common functionality such as exposure compensation or can be simply set to do nothing. There’s also the option to put the lens into the crop mode of 1.6x, giving an equivalent focal length of 24-56mm.
The two switches on the lens consist of the AF/manual focus and image stabilization on/off switches. The lens also comes with its own petal-shaped hood.
Moving to the inside workings, there are 16 elements arranged in 12 groups (two of these being Ultra-Low Dispersion and three aspherical), with a constant aperture range of f/2.8-f/22. The lens elements have been treated to Air-Sphere and fluorine coatings to reduce things like lens flare and for general protection. There are also nine rounded diaphragm blades, which should provide a nice bokeh effect, built-in stabilization up to five stops and the latest Nano USM AF system.
The Canon RF 15-35mm f/2.8L IS USM in Use
First up, the anomalies of the Canon RF 15-35mm f/2.8L IS USM to see how detrimental they are to the final image. Wide-angle zooms usually exhibit some form of barrel distortion, but the 15-35mm keeps this effect well under control. Unless you’re very close up to a subject, straight lines only start to look slightly out of shape at the extreme edges and close-up, which can be easily corrected in software.
Vignetting is apparent when the lens is at f/2.8 and at its widest focal length while stopping down to f/4, things clear up nicely and by f/5.6 effectively disappear. This seems to be the findings at all focal lengths.
Chromatic aberration is also a telltale sign on a wide-angle zoom, but the effect was surprisingly minimal. Very tiny amounts in the form of purple or blue fringing only just reared their head when the sun was in frame and on high contrast areas. But other than that, the effect was kept well in check.
The lens can also get quite close up to a subject with a minimum focusing distance of 28cm. Not exactly a macro mode, but getting quite close up with a wide-angle view can produce some interesting scenes. Especially when you can blur out the background when the aperture is wide open.
This brings us onto the bokeh effect, which results in some tasty background blur at f/2.8. Subtle blur is usually the standard, blending colors together very nicely. Getting very close to a subject can blur out the background even more, just not to the extent of a telephoto lens. However, you shouldn’t have any complaints in this area, considering its wide-angle nature.
When it comes to the sharpness levels, at the widest focal length of 15mm and fully wide open at f/2.8, center sharpness is very good, peaking at f/4. Slight softness starts to creep in after f/11, while edge softness looks the sharpest at f/8.
In the middle of the range at 24mm the sharpness results are largely the same with center sharpness hitting its zenith at f/5.6, before tailing off again at f/11. At sharpness at this focal length hits its peak between f/5.6-f/8. At 35mm, center sharpness is relatively good at f/2.8, being the best at f/5.6-f/8, while corner sharpness looks the best between f/8-f/11.
Lastly, the AF system is both fast and quiet and I only noticed a few incidents of focus hunting when in very low light conditions. The image stabilization system, while not always a necessity on a wide angle zoom, allows extremely low shutter speeds, which makes this lens a very good worker in low light.
How Does It Compare?
Comparisons at this point are thin on the ground, as we have to look at the RF range solely. This is why we’ve left out the usual comparison table.
But, if you wanted to look at lenses with some overlap there is the more expensive Canon RF 28-70mm f/2 L USM, which benefits from a wider apertur and the Canon RF 35mm f/1.8 IS Macro STM is more of a standard walkaround lens, and will not have the ultimate resolution.
There’s also the optional Canon RF 50mm f/1.2L USM, which has the largest aperture of the lot, but is at a standard focal length and not exactly the widest.
As with the other RF lenses in this lineup, they almost feel ahead of their time, waiting for the equivalent camera bodies to catch up. When fully pro level mirrorless camera bodies emerge from Canon, it’s likely then when these lenses will fully shine.
As for the lens itself, the Canon RF 15-35mm f/2.8L IS USM provides extremely sharp images, with a nice array of features aimed at the working photographer. It is a heavy beast, especially on an RP body, but the ultimate resolution quality should counter any other issues, with this one is likely to be the standard in years to come.
There’s also the high price tag to consider. Probably worth it for this level of lens and the must-have lenses in the future, but a high-resolution sensor is in order to get the best results. Like the other lenses in this lineup, the Canon RF 15-35mm f/2.8L IS USM is one to revisit in the future, when we can really put it through its paces.