Lens Test: Canon RF 24-105mm
The RF 24-105mm f/4-7.1 IS STM is an excellent everyday enthusiast lens for EOS mirrorless – but is speed an issue?
How will the delightfully budget RF 24-105mm fair in our comprehensive lab tests? Find out!
The Canon RF 24-105mm f/4-7.1 IS STM is a smaller, lighter and more affordable alternative to the Canon RF 24-105mm f/4 L IS USM – the ‘kit’ lens that released with the Canon EOS R mirrorless back in 2018.
The L-series version performed better than its kit lens designation might suggest, and it remains a formidable all-purpose optic – so much so that it sits at the top of our best Canon RF lenses guide. But where does the new non-l version come in? And the biggest question – why the move to f/7.1, and what effect does this have on the way the lens functions? Let’s take a look…
Build and handling
The first thing you notice about the new 24-105mm is the form factor. Compared to the f/4l it feels sleek and slender, though no less sturdy. Unsurprisingly, the f/4-7.1 seems to have been designed to pair with the RP in mind – and it has to be said that they make an ideal pairing.
The zoom ring doesn’t have quite the feathery glide as the one on the f/4l, though it achieves just the right balance between tightness and smoothness. It lacks a LOCK button to stop the mechanism telescoping open, but creep isn’t an issue. Where the f/4l featured three rings to accommodate manual focus, zoom and control, the f/4-7.1 only has two. This means the control ring does double duty as a customizable input (aperture, shutter, ISO, white balance or exposure compensation) and manual focus, which is toggled by flicking the FOCUS / CONTROL switch on the side of the lens.
Performance
What’s the deal with the unique f/4-7.1 aperture? After all, most
The zoom ring doesn’t have quite the feathery glide as the one on the f/4l, though it achieves just the right balance
zoom lenses of this kind feature the standard f/3.5-5.6 aperture range (including the equivalent Canon EF 24-105mm f/3.5–5.6 IS STM). The f/4 aperture is only available for a couple of millimetres. By the 50mm ‘standard’ focal length you’ve hit f/5.6, and the speed limit of f/7.1 is in play before you hit 85mm. The result is that, whatever you’re shooting, you’re going to need one of three things: lots of ambient light, lots supplemental light, or a willingness to crank up your ISO, or ramp down your shutter speed.
As Canon noted, the higher ISO performance of the EOS R and RP mean that bumping this value doesn’t have nearly the detrimental effect it used to. We never exceeded ISO2000, though that was in a bright and airy room with the aid of continuous light.
With regard to how the slower aperture affects focusing speed, we can say it really wasn’t an issue with this lens. Whether taking portraits, or focusing on flowers blowing in the wind at 105mm f/7.1, the AF never dragged its heels. Slower apertures do have a negative effect on shallow DOF images, though.
Techie stuff aside, we were pleased with the shots. Centre sharpness is impressive throughout the focal and aperture range, and distortion is well controlled from standard through to the tele end. The compromise is in corner sharpness, and distortion and fringing at the wider end – but this can be easily fixed in post.