Features and Handling
Performance
Verdict
Specification
What an exciting prospect, a brand new set of lenses for a brand new range of mirrorless cameras, complete with a brand new mount. Canon are leading the pack as various marques storm into this new area of the market with competitive full frame offerings. So first up is the Canon RF 24-105mm f/4L IS USM for the new Canon EOS R 30mp full frame mirrorless camera. Let's take a close look and see how this concept stacks up in terms of performance and also perhaps as an alternative to the traditional DSLR.
Canon RF 24-105mm f/4L IS USM Handling and Features
Starting our tour of the lens at the front, we have the usual bayonet fit petal lens hood. There is a release catch provided, so there is no chance that the hood will become detached accidentally. Within the bayonet is a standard 77mm filter thread. The overall exterior is very nicely finished and is weather sealed. The front and rear elements are also Fluorine coated to repel dust, grease and moisture.
Immediately behind the hood is a Control Ring. When the shutter button is half depressed this dial will change the aperture setting. There are situations where this could prove to be very convenient, perhaps reducing the amount of vibration that would ensure should the usual main dial on the camera be used during video shooting. This dial is provided with very smooth click stops.
Next we have the manual focus ring, electronically operated and beautifully damped. Just right. There is no distance scale, but in MF mode a scale is displayed in the viewfinder and on the rear monitor. There is no depth of field scale. Focusing is down to 0.45m, a maximum magnification of 0.24x, respectably close.
The final control ring is the zoom ring, clearly marked with accurate focal lengths. One excellent handling point is that towards the front of the zoom ring the diameter of the lens tapers down towards the camera body. This means that the ring can be found by touch, as can the focusing. It's a simple and clever idea.
Closer to the camera the barrel is plain apart from three switches. The lock switch prevents zoom creep whilst the camera is being carried. The AF/MF switch and stabiliser on/off switches are self explanatory.
Finally, we have the new bayonet mount. The register distance for mirrorless cameras is of course far less than for a DSLR as there is no need to design lenses with the mirror box in mind. Theoretically, lenses might be more compact and might even be better quality if retrofocus designs do not have to be used. There is little evidence of compactness here though, and the lens weighs in at a substantial 700g as well. It is a constant f/4 optic, and comprises 18 elements in 14 groups. It has a diaphragm of 9 blades. Built in IS (Image Stabilisation) is said to offer up to 5 stops advantage. The ring motor uses Nano USM focusing, which is virtually silent and very, very smooth. Zooms in video should be extremely stable.
The mount itself is very wide at 54mm and solidly retained by five fixing screws. This will enable the easier design of wide aperture lenses. The electronic contacts are within the lens throat, so well protected against accidental damage. The mount is not directly compatible with EF and EF-S lenses, but an adapter EF-EOS R is available that enables their use. It provides full electronic contact plus the necessary increase in register distance. There are no optical elements involved, so no reduction in optical quality.
The 24-105mm focal length range is a very practical one for full frame cameras, and especially as the wide end has been extended down to 24mm. It also focuses reasonably close, so all in all a very useful lens indeed, for a wide variety of applications.
Canon RF 24-105mm f/4L IS USM Performance
At 24mm, central sharpness is excellent from f/4 to f/11. Thereafter at f/16 and f/22 it is very good. The edges are very good at f/4, excellent from f/5.6 to f/8, very good from f/11 to f/16 and then tail off at f/22, although still can be described as good.
At 35mm, central sharpness is excellent from f/4 to f/8, very good from f/11 to f/16 and good at f/22. The edges are very good from f/4 all the way through to f/16, reducing to good at at f/22.
At 70mm we have a very similar performance. The centre is excellent from f/4 to f/11, very good at f/16 and good at f/22. The edges are very good from f/4 to f/16 and good at f/22.
At 105mm, the centre is still performing well, being excellent from f/4 to f/11, very good at f/16 and good at f/22. The edges finally start to give way a little, being only fair at f/4, good at f/5.6 but perking up to very good at f/8 and f/11. Performance at f/16 and f/22 is good.
Canon RF 24-105mm f/4L IS USM MTF Charts
How to read our MTF chartsThe blue column represents readings from the centre of the picture frame at the various apertures and the green is from the edges.The scale on the left side is an indication of actual image resolution as LW/PH and is described in detail above. The taller the column, the better the lens performance. For this review, the lens was tested on a Canon EOS R using Imatest. |
CA (Chromatic Aberration) is not a problem at the centre of the image, but at the edges it is clearly visible, especially on demanding subjects such as branches against bright sky. However, for the purposes of the review all in camera corrections are turned off so it is possible to correct various aberrations in camera or in other software.
Canon RF 24-105mm f/4L IS USM Chromatic Aberration Charts
How to read our CA chartsChromatic aberration (CA) is the lens' inability to focus on the sensor or film all colours of visible light at the same point. Severe chromatic aberration gives a noticeable fringing or a halo effect around sharp edges within the picture. It can be cured in software.Apochromatic lenses have special lens elements (aspheric, extra-low dispersion etc) to minimize the problem, hence they usually cost more. For this review, the lens was tested on a Canon EOS R using Imatest. |
Distortion can also be corrected in software, but with such aids switched off we find 24mm shows -2.53% barrel distortion, clearly visible where straight lines are at the image edges. 35mm has +0.89% pincushion distortion, and then it's pincushion all the way, measuring +1.72% at 70mm and +1.96% at 105mm.
Bokeh is very pleasant, with commendably rounded highlights and smooth gradation in the out of focus areas.
Flare in extreme situations does have the effect of reducing contrast. However, the control of unwanted artefacts is excellent.
Vignetting at 24mm shows -2.4 stops of corner darkening at f/4, reducing to -1.9 stops at f/5.6 and then stabilising throughout the range at -1.6 stops.
At 35mm, f/4 to f/8 shows -1.6 stops and thereafter from f/11 to f/22 this levels out at -1.4 stops.
At 70mm we have th best vignetting figures, with -1.1 stops at f/4, -0.8 at f/5.6, -0.7 at f/8 and f/11 and -0.6 at f/16 and f/22.
At 105mm, we see -1.9 stops at f/4, -1.6 stops at f/5.6 and then -1.2 stops all the way though to f/22. Of course this darkening of the corners can be beneficial to some images, but if unwanted can be corrected in camera or in other software.
The IS (Image Stabilisation) system promises a 5 stop advantage. This figure proved on test to be absolutely correct. Images were still crisp 5 stops beyond what could be reasonably expected. At 6 stops the system lost it and we had camera shake. An excellent performance that matches the claims.
Canon RF 24-105mm f/4L IS USM Sample Photos
Canon RF 24-105mm f/4L IS USM Other sample images
Canon RF 24-105mm f/4L IS USM Aperture range
Value For Money
The Canon RF 24-105mm f/4 L IS USM is priced at £1119.00. With the EOS R body and the EF adapter the kit costs £3269, which effectively gives us the lens for £920. Buying as a kit would seem to be the way to go.
Using the adapter, the EF and EF-S lenses can be used, so that is an alternative possibility from the Canon range.
Some similar lenses for comparison might include:
Sony FE 24-105mm f/4G OSS, £1199
Canon EF 24-105mm f/4L IS II USM, £1019
Sigma 24-105mm f/4 DG OS HSM, £599
Nikon AF-S Nikkor 24-120mm f/4G ED VR, £1079
The new lens would therefore seem to be par for the course compared to similar marque lenses.
Canon RF 24-105mm f/4L IS USM Verdict
If we look at this just as a lens for a camera system then the cost is about right and the performance is excellent. So, for users of this system this is a very fine standard zoom and in fact pretty much the only choice at the moment. It absolutely delivers the goods.
If we look at this as part of a new mirrorless system and ask is it good value for money compared to the current DSLR systems, then that is quite a different equation to balance. Weight and bulk are not particularly reduced, so any advantage is probably in terms of silent, mirror-free and therefore vibration free operation. Of course individuals will prefer the handling of one or the other and buy accordingly.
Whatever our requirements are though, one thing is certain and that is that this is a very, very fine lens and Highly Recommended.
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The Canon RF 24-105mm f/4L IS USM is a very versatile lens with a very impressive performance. |
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