Canon has certainly been expanding their RF lens range of late with some very tasty top end prime and zoom lenses. The Canon RF 24-240mm f/4-6.3 IS USM marks the first middle-of-the-road, super zoom lens for those who want an all in one solution that saves carrying around a bunch of primes and zooms and doesn’t break the bank.
Although these wide focal length zooms don’t usually have the same optical or build characteristics of the L-series, Canon say that this lens is ‘RF quality.’ So, let’s see how the Canon RF 24-240mm f/4-6.3 IS USM performs in the real world and if it can serve as a one stop, all-in-one solution.
Design
It was initially anticipated that the 24-240mm zoom lens would be a heavyweight beast, especially on an EOS RP camera. However, the lens comes in a respectable weight of 751.26g which is roughly the same as a top end, small prime or zoom lens.
The 24-240mm follows the latest lens fashion of being a straightforward, simple design. The lens barrel itself is made from a plastic, composite material. Not L-series solidity, but still very robust feeling.
The lens barrel consists of the zoom ring and the RF implemented control ring. The latter can be programmed to change many exposure settings, such as ISO and exposure compensation. There are also three switches on the lens barrel. A lens lock switch, focus/control switch and stabilizer on and off switch.
The Canon RF 24-240mm f/4-6.3 IS USM encompasses the latest nano USM AF motor, which takes the best bits of the USM and STM motors to bring the quickest and most quiet shooting scenarios to benefit both stills and video. The other bonus on this lens is the five stops of compensation, image stabilization system. A great addition for handheld shooting, but also beneficial as the lowest aperture range is f/4-6.3, so low shutter speeds should be guaranteed.
As expected, inside the lens is quite a bit of glass, consisting of 21 elements arranged in 15 groups, along with a seven blade, rounded diaphragm. The closest focusing distances is 50cm, which isn’t exactly macro mode, but this lens will most likely be the most used for more distant subjects, so this area shouldn’t be a problem. The front of the lens features a 72mm filter thread, which is nonrotating and should be able to fit a variety of filters.
Lastly, the lens comes with a few accessories such as the E-72 II lens cap and a rear lens cap, with items like an EW-78F lens hood being optional extras.
The Canon RF 24-240mm f/4-6.3 IS USM in Use
The nano AF motor of the Canon RF 24-240mm f/4-6.3 IS USM definitely performs as stated. With stills shooting, focusing only started to trip up in very low light conditions and at the extreme of zoom. But, otherwise it’s a very quick and quiet operator. While shooting video, we didn’t hear any audible noise, with no whirring when changing focal lengths.
The image stabilization system works as expected. We didn’t push past three stops, just to make sure all footage was as sharp as possible, but the claimed five stops of compensation is highly achievable. The system is never going to completely compensate for shaky hands, so the usual methods for bracing the camera are needed and the stabilization system used as a backup more than anything.
Sharpness levels on a super zoom usually suffer due to the extended zoom range. Having 10 times zoom in this lens could have been a problem but the image quality is generally very good in the center until you reach full zoom. At 240mm there is noticeable softness in the corners, but the center of the frame still stays relatively sharp.
The lens performs much better at the shortest focal lengths, with reasonable sharpness across the frame. It’s also of note that the lens uses digital and optical correction, which is most obvious when looking at the straight RAW files. A lens profile will be needed to correct anomalies and without it, the corner of images do suffer from heavy shading.
Outputted JPEGs, have corrections applied, so no worries in that regard. Digital correction may not seem the best way forward, especially from where the technologies come from. However, the resulting images do have an extra bit of refinement. Most probably, this is something we will see more and more in the low to middle range of lenses in the future.
The Canon RF 24-240mm f/4-6.3 IS USM actually performs very well at the widest apertures, so there’s no need to stop down to increase sharpness, mainly in the center of the frame. Edge softness seems to be the area most hit at the different zoom levels, being the softest at the widest and most telephoto ends of the spectrum, while looking the best in the 50-100mm range.
The lens suffers from some color fringing when the aperture is wide open. Continually stopping down reduces the effect, but it can be clearly be seen in high contrast areas. Digital correction can deal with most of these artifacts, but it’s most obviously seen on plain RAW files.
Lens distortion is also evident, the most at 24mm where it is quite high and you will definitely need a lens profile for correction. After 50mm, the effect is more like pin cushioning, but still very evident.
Bokeh is achievable with this lens, most obviously at the telephoto range. Reasonable background blur quality, but not in the same ballpark of quality as you would find in a f/2.8 or larger aperture.
Overall, the image quality is very good, with lots of contrast and saturation in the right circumstances. You’ve always got to be mindful of the soft edges, but overall, having such a wide zoom range is loads of fun to use and although it’s not of the quality of a high-end zoom or prime, the quality is still very respectable.
How Does It Compare?
As the Canon RF 24-240mm f/4-6.3 IS USM is the first middle-of-the-road RF super zoom from the company, it’s hard to make comparisons at this stage. Thus, the omission of the usual comparison table.
An EF lens, in theory, can be used with an adapter on an RF mount camera, but then you have to factor in the cost of the adapter and will the lens work as seamlessly as a native RF lens (in theory, should).
As there’s now a good bunch of RF lenses on the market in the L-series, these could be an alternative, but you will have to fork out more money and have a less wide focal range. However, the benefits of stepping up to the L-series range means better build quality and should be better optics.
Conclusion
As a midpriced superzoom, the Canon RF 24-240mm f/4-6.3 IS USM acts as a good all-rounder and will especially appeal to enthusiasts who may want a bundled kit lens or simply an all-in-one solution.
The optical quality is better than expected from a superzoom, the image stabilization and AF motor work as expected and generally, the lens is great fun to use. It can suffer from softness in the corners, especially wide open and if you don’t use a lens profile, images can suffer from heavy shading in the corners. Therefore, profile correction is a must with this lens.
Digital correction may not be everybody’s cup of Darjeeling, but it’s definitely part of the workflow these days. This lens proves that digital correction does now work in our favor and superzooms from now on in seem to be much better than what we were used to of old. In this regard, if you want an all in one lens with good optics, this lens is a good option to shortlist.
