Price when reviewed
Canon has been slow to grow its RF-S lens range, so it’s good to see the RF-S 10-18mm F4.5-6.3 IS STM join the line-up as an ultra-wide-angle zoom. It makes a good pairing with the RF-S 18-45mm F4.5-6.3 IS STM or RF-S 18-150mm F3.5-6.3 IS STM, but it would be nice to see Canon introduce a few constant-aperture lenses to the range. That aside, initial testing indicates that the RF-S 10-18mm F4.5-6.3 IS STM is a solid performer and an attractive ultra-wide addition for Canon APS-C format R-series camera users.
The Canon RF-S 10-18mm F4.5-6.3 IS STM, reviewed here, is a compact and lightweight ultra-wide lens for Canon APS-C format mirrorless cameras like the R7. It has an effective focal length of 16-28.8mm which makes it an attractive lens for high-impact landscapes, travel and street photography.
As it has the RF mount, the RF-S 10-18mm F4.5-6.3 IS STM can be used on full-frame cameras such as the Canon R6 II and Canon R5, but they crop the images to APS-C format to match the optic’s image circle.
The Canon RF-S 10-18mm F4.5-6.3 IS STM is built with 12 elements organised into 10 groups. Among these elements are a PMo (plastic-folded) component near the rear of the lens and a pair of UD (Ultra-Low Dispersion) elements. These special elements help to minimise optical aberrations and image distortion.
Canon states that, thanks to the RF mount, this lens outperforms its EF-S counterpart, the EF-S 10-18mm f/4.5-5.6 IS STM, particularly when it comes to edge-to-edge image clarity.
Autofocusing is handled by Canon’s STM (Stepping Motor) technology, which is designed to be quiet and smooth, ideal for both still photography and video capture. When this system is in use, the closest focusing distance is 14cm, which gives a maximum reproduction ratio of 0.23x. However, switching to manual focusing reduces the distance to just 8.6cm between the subject and sensor, which at the 10mm end of the lens, boosts the magnification to 0.5x or half-life-size.
The lens comes loaded with a 4-stop image stabilisation system but if it’s paired with a camera that has in-body stabilisation (IBIS), you can get up to 6 stops of shutter speed compensation.
Canon sells the lens without a lens hood, but the EW-53B is available as an optional extra.
Canon has used a collapsible design for the RF-S 10-18mm F4.5-6.3 IS STM and when it’s fully-retracted, it measures just 44.9mm in length. It also weighs a mere 150g – no doubt helped by the use of plastic rather than metal for the mount. This means that the RF-S 10-18mm F4.5-6.3 IS STM is smaller and lighter than the EF-S 10-18mm f/4.5-5.6 IS STM which is for Canon’s APS-C format DSLRs.
The lens features a dual-purpose focus and control ring, which you can be customised to match your shooting preferences.
As you’d expect with such a small, light lens, it looks very neat on a camera like the Canon R7. It has no switches or buttons, just the ridged zoom ring and knurled control / manual focus ring.
It takes a short turn of the lens’ zoom ring to take it from the collapsed state to extended and ready for action. The are 5 focal markings running from 10mm through 12, 14 and 16mm to 18mm. Zooming from 10mm to 18mm requires less than a quarter rotation of the ring, so you it’s quick and easy to move from one focal length to another.
I was invited to Canon UK’s headquarters to get hands-on with a pre-production sample of the RF-S 10-18mm F4.5-6.3 IS STM ahead of its announcement. The lens wasn’t suitable for in-depth testing, but I am allowed to post a few images here.
I shot with the RF-S 10-18mm F4.5-6.3 IS STM on the Canon R7 and it captures images with a good level of sharpness. Naturally, the sharpness isn’t as impressive as you’d expect with an L-series lens, but from what I’ve seen so far, it’s a very decent performer.
Some vignetting is visible in the raw images I shot at the widest focal length and aperture. There are even black lines down the sides of some images, which I strongly expect to be gone by the time the lens comes to market and the correction profiles are rolled out. The Jpegs, however, look fine and vignetting isn’t a problem.
The conditions weren’t the best for testing for chromatic aberration and flare, but I haven’t found any issue with either of them so far.
Despite the gloomy conditions, paired with the R7, the RF-S 10-18mm F4.5-6.3 IS STM’s focusing system was nippy and I was able to get sharp shots of foliage moving in the breeze.
I will investigate the curvilinear distortion further when I get a full-production sample in for testing, but straight lines in Jpeg images looks good. In the absence of a correction profile, there’s some barrel distortion evident in the raw files.
These images were captured using a beta-sample RF-S 10-18mm F4.5-6.3 IS STM on the Canon R7.
At 150g in weight and 44.9mm in length, the Canon RF-S 10-18mm F4.5-6.3 IS STM is the type of lens that you can slip in your bag just in case you come across any wide-angle opportunities. It’s early days with our testing, but my first impressions of it are good. The short focusing distance, especially in manual focus mode, adds an extra element of versatility to the mix.
It would be nice to see a metal mount on the RF-S 10-18mm F4.5-6.3 IS STM, but it’s attractively priced.
Canon has taken its time in expanding the RF-S lens collection, so the arrival of the RF-S 10-18mm F4.5-6.3 IS STM as an ultra-wide-angle option is welcome. It complements other lenses in the lineup, like the RF-S 18-45mm F4.5-6.3 IS STM and the RF-S 18-150mm F3.5-6.3 IS STM well. However, it’s about time Canon considered adding some constant-aperture lenses to this growing range to offer even more versatility. Many photographers are unhappy to pay for full-frame lenses to get f/2.8 or f/4 optics for an APS-C format camera.
