Canon RF 24-105mm f/4L IS USM Review
Canon RF 24-105mm f/4L IS USM Introduction
The RF 24-105mm f/4L IS USM is a professional standard zoom lens for Canon's new full-frame mirrorless camera system. Featuring a Nano Ultrasonic Motor for smooth, precise and quiet continuous auto-focusing, Fluorine coatings on the front and rear lens elements, 9 rounded diaphragm blades for smoother bokeh, a zoom lock switch to prevent lens creep, and image stabilisation offering a claimed 5-stop advantage, the weather-resistant Canon RF 24-105mm f/4L IS USM is a capable all-rounder. The Canon RF 24-105mm f/4L IS USM officially retails for £1,119 / €1,319.99 / $1,099.99 in the UK, Europe and the USA respectively.
Ease of Use
The Canon RF 24-105mm f/4L IS USM isn't too big and bulky considering the versatile focal range that it covers, weighing in at 700g and measuring 10.7cm in length, both smaller and lighter than the DSLR equivalent, although it does extend to 15cm when the lens is set to 105mm.
Build quality is excellent. The Canon RF 24-105mm f/4L IS USM feels very solid in your hand, even if it is mostly made out of plastic, and it features enhanced resistance to shock and vibration and weather-proofing too. The focusing ring is generously wide, and has a ridged, rubberised grip band.
A new feature for RF lenses is the Lens Control Ring at the end of the lens barrel, which can be used to control certain key camera settings. Although not a new idea in the wider photography world, this is the first time that Canon have incorporated this idea into their interchangeable lenses.
The Canon RF 24-105mm f/4L IS USM boasts Image Stabilisation which Canon claims offers an advantage of up to 5 f-stops over lenses without a stabilizer. This is activated via the Stabilizer On/Off switch on the side of the lens. If the camera body supports it, Canon's IS technology is also able to detect intentional panning movement and automatically switch from the Normal IS mode to the Panning IS mode.
The Lock function switch is a useful feature that helps protect the lens. Set the focal length to 24mm and move it to the Lock position to prevent the zoom mechanism from creeping when the camera is pointed down or in storage.
The final control on the lens barrel is a focus mode switch with the usual AF/MF settings. Note that this lens usefully offers full-time manual focusing even when AF is selected.
The Canon RF 24-105mm f/4L IS USM lens has a generously wide focus ring. There are no hard stops at both ends of the range, making it more difficult to set focus at infinity. Polariser users should be pleased that the 77mm filter thread doesn't rotate on focus.
When it comes to auto-focusing, the Canon RF 24-105mm f/4L IS USM zoom is a very quick performer, taking under 0.10 seconds to lock onto the subject when mounted on the Canon EOS R camera that we tested it with.
We didn't experience very much "hunting" at all, either in good or bad light, with the lens accurately focusing virtually all of the time. It's also a very quiet performer, thanks to the built-in Nano USM (Ultra Sonic Motor), which makes this lens well-suited to video recording.
The lens ships with a petal shaped lens hood (EW-83N) and a soft case (LP1319).
At the 24mm focal length the angle of view is 74 degrees.
Field of view at 24mm
At the 105mm focal length the angle of view is 19 degrees.
Field of view at 105mm
Chromatic aberrations, typically seen as purple or blue fringes along contrasty edges, are very well controlled with this lens - the examples below show the worst-case scenario.
With the lens wide open, you can see some obvious light fall-off in the corners at both ends of the zoom range. Stopping down helps, although to completely get rid of this phenomenon, you will need to use an f-stop of f/8 or smaller.
Barrel distortion is evident at the 24mm wide-angle focal length, but it disappears completely by 35mm.
Vignetting at 24mm
Vignetting at 105mm
The Canon RF 24-105mm f/4L IS USM is not a macro lens. The close-focus point is at 45cm from the film/sensor plane, and Canon quotes a maximum reproduction ratio of 0.24x for the lens when set to 105mm. The following example illustrate how close you can get to the subject.
Bokeh is a word used for the out-of-focus areas of a photograph, and is usually described in qualitative terms, such as smooth / creamy / harsh etc. Canon have employed an iris diaphragm with nine rounded blades for a pleasing rendering of the out-of-focus highlights. Based on what we have seen, we can say that they have largely succeeded. Below you'll find some examples, but you are also encouraged to check out our sample images.
In order to show you how sharp this lens is, we are providing 100% crops on the following pages.