With the Canon RF 15-35 mm f/2.8 L IS USM, Canon has put on quite  a performance. It actually offers everything that you would want in a wide-angle zoom.

The Canon RF 15-35 mm f/2.8 L IS USM is the first f/2.8 zoom for the Canon R system. For many photographers, it is part of a set of three: wide-angle zoom, standard zoom, and telephoto zoom. The Canon RF 24-70 mm f/2.8 L IS USM and the Canon RF 70-200 mm f/2.8 L IS USM complete the set and are now also available. Together, these three zooms offer a range from super-wide angle to substantial telephoto in combination with high brightness. As a photographer, you can use it to photograph almost everything that you want. The Canon RF 15-35 mm f/2.8 L IS USM is a special lens. Partly because it has a millimeter more range on the wide-angle side than its SLR counterpart, the Canon EF 16-35 mm f/2.8 L USM III. That does not seem much, but a millimeter more or less on a super-wide angle makes quite a difference. But the most striking aspect of the Canon RF 15-35 mm f/2.8 L IS USM is the image stabilization. This is the first bright wide-angle zoom from Canon that has it.

Until the arrival of the Canon RF 15-35 mm f/2.8L IS USM, you always had to choose between an f/2.8 version without image stabilization or an f/4 version with. That’s no longer necessary. It makes this 15-35 mm the most versatile wide-angle zoom from Canon ever. This is further enhanced by the ability to use regular screw filters on this lens. Certainly for landscape photographers, this makes it possible to work with polarization or gradient gray filters, for example. But videographers will also appreciate the option because it makes it easier to work with ND filters.

BUILD AND autofocus

As we are used to from Canon L-series lenses, this Canon RF 15-35 mm f/2.8 L IS USM is also solidly built. Canon has a lot of experience with building lenses, and you can feel that immediately when you pick up the 15-35 mm. There is no play at all in the lens, and everything turns beautifully smoothly. This is a familiar feeling for Canon users. The lens is not really small. It is the same thickness and less than a millimeter shorter than the EF 16-35mm f/2.8L USM.  At 840 grams, it is even 50 grams heavier than the version for the Canon EOS SLR cameras. In comparison with almost all super wide-angle zooms for SLRs with a focal length shorter than 16 mm, though, the Canon RF 15-35 mm f/2.8 L IS USM is lighter. But if you look for example at the new Sigma 14-24 mm f/2.8 DG DN for Sony and Panasonic, then the Canon is heavier. This is really a lens that you buy because of the quality and versatility. If you switched to a mirrorless Canon EOS R because of the dimensions and the low weight, then this is not the ideal wide angle.

Just like the previously released Canon RF 28-70 mm f/2L USM, this Canon RF 15-35 mm f/2.8L IS USM also has a programmable ring at the front. With this you can, for example, set the aperture, the shutter speed or the exposure compensation. That brings the total number of rings to three. Behind the Lens Control Ring is the focus ring and the wide, curved zoom ring. The rings are all different in texture and shape. But they are close together, and it takes some getting used to not to accidentally change your exposure when you actually wanted to adjust your focus slightly. The Canon RF 15-35 mm f/2.8 L IS USM has a 9-bladed diaphragm and holds the same number of lens elements as the EF 16-35 mm f/2.8 L USM: 16. The lens elements have Canon’s SWC and Air Sphere Coating, and the front element has an extra treatment so that moisture and dirt don’t stick as well. The lens has a Nano-USM focusing motor. This ensures fast and precise focus that is also virtually silent.

IMAGE QUALITY

The Canon RF 15-35 mm f/2.8 L IS USM performs excellently in terms of sharpness. We were only able to test the lens on the Canon EOS R, with a 30-megapixel sensor and a low-pass (antialias) filter. That sensor does not really put the lens to the test. The results reflect that as well. The center sharpness is 15 mm high, with a small gradient to the corners. That sharpness in the center drops off a bit at the other focal lengths, but then the corners pick up a bit. That gives you very even sharpness over the entire range. The lens achieves the best results at all positions with f/5.6 and f/8, but the difference from larger apertures is so small that you don’t need to stop down for the optimum sharpness. An image like this generally means that the lens will also be able to handle sensors with more pixels. 

Bright wide-angle lenses almost always suffer from vignetting. The Canon RF 15-35 mm f/2.8 L IS USM is no exception. And of course you see that the most at full aperture in the extreme wide-angle position. With almost 3 stops in RAW, it’s quite a lot. In the jpegs, you only see half of that due to the corrections in the camera. Once you stop down a stop or zoom in on something, it quickly decreases. At f/4, it’s less than a stop in the jpegs over the entire range. That’s not bad, although you have to take into account that with a lot of contrast you have a little less dynamic range in the corners due to the corrections.

The Canon RF 15-35 mm f/2.8 L IS USM is also not completely free of distortion. In the RAW files, the distortion varies from more than 1% barrel-shaped at 15 mm to more than 2% pincushion-shaped at 28 mm. But you never actually see that. In the viewfinder and the jpegs, the image is already corrected by the camera, and with most RAW converters, the files get an immediate correction when you open them. What you see is never more than half a percent pincushion-shaped distortion. However, that distortion is not beautifully even; there’s a bit of a wave in it. That makes it difficult to get rid of that last bit of distortion in really critical shots.

IMAGE STABILIZATION

The Canon RF 15-35 mm f/2.8 L IS USM is the first bright wide-angle zoom from Canon with image stabilization. That’s long overdue. Almost all cameras from competitors have stabilization in the body. And that makes every lens automatically a stabilized lens. You may disagree on the effectiveness of stabilization in the body compared to stabilization in the lens, but the fact is that stabilization in the body is always better than having no stabilization. Fortunately, with the EOS R system, you no longer have to choose between a bright wide-angle zoom or a stabilized wide-angle zoom. The Canon RF 15-35 mm f/2.8 L IS USM is both. And the stabilization works great. Canon claims 5 stops, and our test confirms that. It makes the lens even more useful in low light.

Canon RF 15-35mm f/2.8L IS USM SAMPLE IMAGES

Curious about the performance of the Canon RF 15-35 mm f/2.8 L IS USM in practice? Click on the button below and visit our renewed web gallery with sample images. The images can be downloaded in full resolution to be viewed at 100%.

ConclusiON: REVIEW Canon RF 15-35mm f/2.8L IS USM oN Canon EOS R