As Canon starts to round out the lens range for the Canon EOS R and EOS RP bodies, it makes sense to have a top-quality zoom that covers the most useful focal lengths. For the DLSR version, it was the 24-70mm focal length and now for the mirrorless format, it’s the Canon RF 28-70mm f/2L USM.
To produce the best quality zoom lens, Canon hasn’t made the lightest or smallest lens possible, which would be most befitting of a mirrorless camera body. Instead, it comes as a larger and heavier offering than its DSLR counterpart.
The new RF 28-70mm now measures 104 x 140mm and weighs a substantial 1,430g. It also costs a lot more than its DLSR counterpart, which is understandable due to the larger f/2 aperture and fancier internal workings. The filter thread size has also been increased from 85mm to 95mm.
Compared to the DSLR lens, this mirrorless version starts at 28mm rather than 24mm, meaning you lose a bit at the wide-angle end of the range. Canon has gone with all-out quality on this lens build, which should also be a better low-light performer than previous versions.
There is the argument that the high price point is justified as this lens covers the same reach as a bunch of high-quality prime lenses, with an aperture that almost goes as wide. There’s also the question of the lack of image stabilization on this lens, but this can be justified as the feature wasn’t present on the old lens and the increased weight could easily put off many users.
Let’s have a closer look at what the RF 28-70mm f/2L USM has to offer.
Design
Internally, the optics comprise of 19 elements arranged in 13 groups, with two ground aspherical, two Glass-Moulded (GM) aspherical, two UD (Ultra-low Dispersion), and one Super UD element. The lens also has a bunch of special coatings, which include a WC (Subwavelength Structure Coating) and ASC (Air Sphere Coating) which reduce reflections and increase clarity. The lens features a nine-blade rounded diaphragm, which should produce quality bokeh effects.
Autofocusing is handled by a ring-type Ultrasonic Motor (USM) with full-time manual focus override provided by the ridged ring around the lens barrel. The zoom ring on the lens barrel turns extremely smoothly, with a slightly different ridged feel to the others. At the end of the lens is the new configurable control ring which can be set to adjust things like exposure compensation.
The lens on the whole is a straightforward and simple design, with the usual Canon L-series build quality, which is fully weatherproofed and a generally very smooth feel.
The Canon RF 28-70mm f/2L USM in Use
When this lens is strapped to an EOS R or EOS RP camera body, it requires a fair bit of cradling to hold its ample weight steady. Although the lens does make the whole camera setup front heavy, it doesn’t take long to find the right balance point. In use, it simply feels like a 70-200mm zoom in mass and feel.
The autofocus system is extremely rapid, even in low light conditions. While it’s not completely silent, it’s only really the sound of slight internal movements that are the main giveaways.
As for overall sharpness levels, there is no faulting center sharpness throughout the aperture range, even at f/2, where the lens provides heaps of detail. Diffraction starts to take a toll after f/16, but this is also a common aspect of all lenses. Contrast and color are exceptional and the bokeh effects at f/2 are wonderful and creamy, verging on a high-level prime lens.
There is some edge softness exhibited at the widest focal lengths, which does clear up at the more telephoto end. This is only minimal, as with lens anomalies such as chromatic aberration and barrel distortion, which are very low even at the widest aperture.
The wider f/2 aperture is also a great addition for low-light shooting. With the older f/2.8 zoom, it could only go so far in low light and had to be swapped out for a faster prime lens. But, with f/2 at your disposal, there’s an extra stop of light gathering ability available, which makes this lens very versatile.
How Does It Compare?
As there aren’t exactly many 28-70mm RF-compatible zooms at the moment, well, basically none, the Canon RF 50mm f/1.2L USM prime lens could be a good alternative. The RF 50mm sits in the middle of the 28-70mm focal range and has the benefits of a very wide f/1.2 aperture, L-series build quality, and less weight and cost than the 28-70mm.
The images from the RF 50mm are outstanding, even with the aperture wide open. As a straightforward 50mm lens, it can’t be faulted. However, it’s a very weighty lens and although the image quality is immaculate, you’re also spending over $2000 for the privilege, but still cheaper than the 28-70mm.
| Canon RF 28-70mm f/2L USM | Canon RF 50mm f/1.2L USM | |
| Optics | 19 elements / 13 groups | 15 elements / 9 groups |
| Diaphragm Blades | 9 rounded | 10 rounded |
| Filter | 95mm | 77mm |
| Weight | 1430g | 950g |
Conclusion
There’s no denying Canon has produced an excellent new workhorse lens in the form of the Canon RF 28-70mm f/2L USM. Images from this lens are super sharp, with lovely renditions of color and saturation. The f/2 aperture is a great addition for low-light shooting and the bokeh is wonderful.
On the downsides, there is some edge softness, especially when the aperture is wide open, and it is obviously a heavyweight beast. This point alone may be a deciding factor for many in the future, as the lighter weight of a mirrorless camera body is in part to save bicep muscles on a long day’s shoot. This means if you’re planning on using this lens on a regular basis, you better start doing some high-intensity bicep curls if you haven’t already.
However, if you can justify its asking price and weight, the Canon RF 28-70mm f/2L USM looks like it’s going to be the new standard moving forward.
