Out of the latest crop of RF lenses, the release of the Canon RF 28–70mm f/2 L USM is arguably the most significant. The 24-70mm zoom has traditionally been the go-to standard, as it encompasses all the most useful focal lengths and produces great quality images. As Canon is going down the full-frame mirrorless route, it makes sense to make an equivalent zoom, which is what we have here.
There’s obviously changes from the standard DSLR version, which we will dig into later. But, the main criteria here is this new lens is the latest and greatest version and should be as rock-solid as 24-70mm versions of the past.
The Canon RF 28–70mm f/2 L USM follows the rest of the RF zooms in design and being in the more heavyweight category. Large lenses usually mean lots of glass which is the case here. This lens weighs in at a not-so-light 1430g. This is substantial, but if you consider that it’s taking the place of a good few quality prime lenses, the weight doesn’t feel that bad.
The lens barrel itself is made from polycarbonate, is fully weatherproof, and has a largely sparse layout. Gone is the usual distance scale, with only three rings and a few switches as external features.
Closest to the back of the lens is the zoom ring, which has a rubberized ridged feel. Not as wide as on the other RF lenses, but still substantial enough to get a firm grip. Next along is the manual focus ring, which has a slightly different textured feel and lastly, nearest the front of the lens is the control ring which can be programmed to change things like exposure compensation.
There’s no image stabilization on this version, which seems a shame, but it’s made up for with a maximum f/2 aperture. This is significant as it provides a stop more of light than a regular f/2.8, which is also the reason for its extra bulky dimensions.
The other external features on the lens consist of a Lock function switch to hold the lens barrel at a certain focal. The other switch being the usual AF/MF control. Upfront is a whopping 95mm filter thread, which is a bit of a jump from the past 77mm, that doesn’t rotate. Also, included is a petal-shaped lens hood, much smaller than the lens hoods of old.
As for the internal specs, the aperture range goes from f/2-f/22, with nine rounded diaphragm blades. The optics are arranged from 19 elements in 13 groups, which also have Ultra-Low Dispersion (UD) elements to reduce flaring and ghosting.
The other thing to note is that Canon has lopped off 4mm from the wide-angle end of things, being 28mm instead of 24mm. Original versions of this lens came in at 28mm, which means that with this lens, it’s a bit of give-and-take having a slightly wider aperture while having a slightly less wide-angle view.
The Canon RF 28–70mm f/2 L USM in Use
Coming from the regular f/2.8 version of this lens, the Canon RF 28–70mm f/2 L USM feels almost like a heavyweight prime. It’s obviously very front heavy on the current Canon mirrorless bodies, which basically means you have to have a firm handhold to keep everything steady.
As for lens anomalies, chromatic aberrations like purple or blue fringing are hardly noticeable, even when the aperture is wide open. Which means no complaints in this department.
Vignetting or light falloff is evident in the corners, but in small amounts when at f/2.8 at both ends of the zoom range. Stopping down to f/4 clears things up nicely. Barrel distortion can be seen at 28mm but starts to dissipate after 35mm. I would say barrel distortion is much less evident on this lens than on the older versions.
The Canon RF 28–70mm f/2 L USM can also get reasonably close to the subject at 39cm, which coupled with a wide aperture can do a great job of punching the subject out from the background. The nine-blade aperture has an iris diaphragm and seems to do a great job of smoothly transitioning colors, with an almost prime lens type look. The f/2 aperture is a great advantage on this lens and as you can now get a prime lens like separation, it makes you want to play with more shallow depths of the field than ever before.
For the autofocusing system, Canon opted for the tried and tested ring-type Ultrasonic Motor, rather than the Nano motor on some of the other RF lenses (maybe due to weight considerations). The USM motor is very quick and quiet and only starts to hunt when in the very lowest of light conditions.
But, how sharp is this thing and is it better than the DSLR version? At 28mm, the center and edges are surprisingly sharp at f/2, looking the best at f/2.8, while starting to tail off again after f/11. The same is largely true at 50mm, with edge and center sharpness being great at f/2 and hitting its zenith from f/2.8 to f/11. At f/16 and above the lens starts to suffer from diffraction.
At 70mm, the results come in the same. At f/2, edge and center sharpness are great with extra detail at f/2.8 going up to f/11. At this point, it feels like this lens is sharper throughout the range than previous versions, with the added benefit of an f/2 aperture.
How Does It Compare?
Lining up the new version of the Canon RF 28–70mm f/2 L USM against the older Canon EF 24-70mm f/2.8L II USM seems initially a little unfair. But, it’s worth checking out the two standards to see if the extra money outlay is worth it.
The EF 24-70mm f/2.8L has 4mm extra at the wide-angle end and doesn’t have image stabilization like the newer lens. It also may be a touch less sharp when wide open, but you can’t fault its optical capabilities. The addition of f/2 in the new lens is going to be its biggest calling card, but you’re also going to have to pay for the privilege.
The EF 24-70mm version is currently far cheaper, which can be fitted to the mirrorless format with an adapter, but it’s not the same as going with a fully native lens.
|Canon RF 28–70mm f/2 L USM||Canon EF 24-70mm f/2.8L II USM|
|Optics||19 elements/13 groups||18 elements/13 groups|
The Canon RF 28–70mm f/2 L USM is clearly a top quality lens and definitely lined up to be the new standard. Its obviously a heavyweight, but as mentioned before this lens will do the job of a bunch of primes, at least from a simpler kit list than anything else.
In terms of sharpness, there are no complaints in the center or edges, even when the aperture is at f/2. Plus, with a new wider aperture, the lowlight capabilities have been vastly improved. Bokeh quality also seems that bit more refined, along with a shallower depth of field, which gives more creative potential.
There is slight vignetting with the lens wide open and slight barrel distortion, but nothing that can’t be corrected in post-processing. Also, there’s the weight consideration, which makes the current mirrorless setup very front heavy. Other than that, this is a fantastic lens worthy of being the new standard.
So, it may be a worthy upgrade from the DLSR version L-series with an equally good build quality, weather-proofed construction, a solid performance, but a high price tag. This makes it out of reach for the enthusiast, who should possibly go for the RF 24-105mm f/4.
But, for those wanting the latest workhorse standard, where optical quality comes before anything else, this is a great option. Now it just needs Canon to release an equally worthy camera body to bring out the Canon RF 28–70mm f/2 L USM’s full potential.