Full-frame mirrorless cameras have become commonplace for us, however, until recently Canon did not release such devices. At that wondrous time, only one brand dominated the mirrorless full-frame market, but everything changed dramatically in the second half of 2018. In the wake of Nikon, Canon just two weeks later showed a vision of its future path that the company will follow for years to come. So, the new Canon EOS R camera with the latest RF mount and four lenses was shown. These were 24-105/4, 50/1.2, 35/1.8 and absolutely unique 28-70/2. Over time, I’m sure we will test all new lenses for the RF mount, and today we have the Canon RF 24-105 mm F4L IS USM kit lens in review.
Since this is our first review of the new line of RF lenses, I feel it is necessary to elaborate on the new mount in more detail. Back in 1987, Canon’s history underwent a historic change – it was the transition from the FD mount to the EF mount, which everyone is now familiar with. However, this transition was more radical than now, since backward compatibility of the mounts was not provided. Now, along with the announcement of its first camera, as many as three adapters were presented, which provide support for working with the old EF mount without restrictions and even expand their functionality: in the case of using adapters with a control ring or a replaceable filter.
The switch to the new lens mount certainly sparked outrage among photographers from Canon EF optics fleet owners. However, the advantages of the new lenses quickly extinguished the wave of indignation, which, I must say, continues to this day, but in its minimal manifestation.
In fact, there are not many key innovations in the mount. The flange diameter remained the same, the number of contacts increased to 12 and the flange distance decreased to 20 mm. These two new qualities allow the development of more advanced lenses not only optically, but also in terms of electronics. Each of the RF lenses is equipped with programmable electronic control rings.
Lenses now transmit information faster, which allows more perfect optical stabilization. Among other things, information about optical aberrations is transmitted to the camera, which makes it possible to correct them more efficiently inside the camera. Most importantly, the increased pin count enables faster autofocus performance.
Reducing the flange distance is dictated not only by the desire of Canon engineers to achieve a smaller camera size, but also to create faster and sharper optics. To what extent this is justified and noticeable in practice, we will test it already in this review. So let’s jump straight to our hero Canon RF 24-105mm F4L IS USM.
Canon RF 24-105mm F4L IS USM
In comments on forums and social networks, you can often find negative comments about the size of modern Canon RF lenses. Indeed, sometimes this is true, for example, for the Canon RF 28-70/2 – this lens is very large and heavy. However, this lens is absolutely unique in its optical characteristics, nothing like this simply exists. But as for the dimensions of our hero 24-105/4, here everything is absolutely the opposite – the new product received smaller dimensions than the analog for the EF mount.
The Canon RF 24-105 mm F4L IS is 107mm versus 118mm for its analog – the 11mm difference is not so significant, but when traveling or mounting the camera on a gimbal, every centimeter is valuable. Diameter 83.5 mm. The weight has also become less – 700 against 795 grams.
Canon RF 24-105mm F4L IS received a more modern design, I must say a rather stylish design, which is difficult to expect from a seemingly simple lens.
There is no focus distance markup here because, like all RF lenses, the focusing ring is electronic. If you switch to manual focus mode, information about the current distance is displayed on the display and viewfinder.
The electronic control wheel on the lens has a discrete stroke, which allows you to tactilely feel a 1/3 stop shift. By default, aperture control is assigned to it, which is quite convenient. But for video shooting, it will be more convenient to assign ISO value control to this wheel.
Almost the entire body of the lens has a plastic body, however, the reliable bayonet mount, which is made of metal, pleases. The lens is dust and moisture resistant. A sealing rubber ring can be observed on the bayonet.
In addition to the control, focusing and zoom ring, there are three more controls on the body. On the right is the “trunk” lock, which is used to fix the lens in the folded state. I must note that even without the use of this lock, the “trunk” does not fall out.
There are two switches on the left side of the lens. The first is responsible for the work of optical stabilization, the second for switching between manual and automatic focus.
Canon RF 24-105mm F4L IS USM Specifications
Despite the fact that the lens has become smaller and lighter, its optical design has become more complex. The design now consists of 18 elements in 15 groups, including 4 aspherical and 2 low dispersion elements. Front and rear lenses are fluorine coated to resist dirt and grease.
The minimum focusing distance is 45 cm, the filter diameter is 77 mm – there are no changes here in comparison with the analogue for the EF mount. But the number of aperture blades has become one less, now there are 9.
According to the manufacturer, the optical stabilization system of the new lens is capable of compensating up to 5 stops. This is one step higher than the EF counterpart. Whether this is really so, we will understand in our tests.
Canon RF 24-105mm F4L IS USM Ground Test
A lens with a focal length of 24-105 mm can be called almost a mega-zoom, but “thanks to” such a wide range of focal lengths, it is quite difficult to achieve good optical performance. It is not for nothing that the most popular universal lens is the 24-70mm, because it finds a compromise between versatility and image quality. Nevertheless, the new RF 24-105mm received an improved optical design, which will certainly affect the image quality. Let’s test it and we’ll start with sharpness.
For sharpening testing we use the standard test world. Below is the crop from the center (left image) and periphery (right image). Switching between diaphragms is carried out using a special menu.
The center over the entire aperture range shows ideal sharpness, which is only slightly reduced at f/20-22. The angle of the frame is not happy with sharpness, but from what is, the maximum sharpness is achieved approximately at the range of f/11-16.
At a focal length of 70mm, the center of the frame at its widest aperture shows a slight decrease in sharpness, and excellent sharpness can be observed from f/4.5 to f/16. If at a wide angle we observed a decrease in sharpness only at f / 20-22, then here the working range is already much smaller – f/4 and f/18-22 show a softening of the picture. But the periphery has become sharper compared to the wide angle, but the quality is still noticeably worse than in the center.
105mm also shows a softening in the center of the frame at the maximum aperture, and at a closed aperture, diffraction depletion begins already at f/16. Sharpness at the periphery has become worse than by 70 mm – in general, I can’t even say that there is a certain range here, where maximum sharpness is achieved.
The lens has excellent resolution in the center of the frame, especially when you remember that we are testing a super universal zoom with constant aperture. But the periphery, unfortunately, is not encouraging. At the edge of the frame, there are significant CAs, the adjustment of which will lead to an improvement in sharpness, but this is already processing, and here we are talking about “raw” indicators.
For chromatic aberration testing, I use a Data Color calibration target and a dedicated world. Shooting is carried out in RAW, then these files are opened in RawDigger and converted to TIFF in order to avoid the influence of various “enhancers” that cannot be disabled by the RAW converter.
Consider the lens for the manifestation of two types of chromatic aberrations – longitudinal and transverse. Longitudinal aberrations appear only at open apertures. Lateral aberrations occur at all apertures and are usually closer to the periphery of the frame.
24mm – Longitudinal and Transverse
Longitudinal aberrations are so minimal that I see no reason to even analyze them. But transverse aberrations are manifested to a large extent, which is not very encouraging.
105mm – Longitudinal and Transverse
At 105mm, the visibility of longitudinal aberrations is even less. At both 24mm and 105mm, this is a slight lilac coloration on high contrast objects that will not be noticeable in the real picture. With transverse aberrations, it is a different matter – it will be quite difficult to avoid them, but it is worth remembering again that they appear not over the entire field of the frame, but only closer to the periphery. It should be noted that at a focal length of 105 mm, the HA crossbars are already weaker, compared to 24mm.
At a focal length of 24mm, barrel distortion can be observed. Focal lengths of 70mm and 105mm already show pincushion distortion. In general, the geometry performance at all focal lengths is very good.
Canon RF 24-105mm F4L IS USM has subtle vignetting. Although it appears up to f / 8, and then completely disappears (which is already good), its effect on the image is absolutely minimal, even at the maximum aperture.
I must say that our hero has excellent glare protection. It was very difficult for me to find an angle at which I could get at least some noticeable flare from the sun entering the frame.
24mm: As you can see, the flare appears next to the sun (approximately 4-5 hours), its outline is minimal. But at 105 mm, catching the flare turned out to be easier.
105 mm: Again, the nature of the flare is such that it is difficult to notice it (located in the lower right corner). The whole bunny hunt took place without a hood. With this in mind, the results are amazing.
When the light hits the lens, the image practically does not lose contrast, which is also very good.
Coma and Astigmatism
Comatic aberrations and astigmatism visually appear in the form of distortion of small points of light in the frame. The absence of such distortion is especially appreciated when shooting city evening landscapes and the starry sky. These two types of aberrations are similar to each other, however, coma appears at the periphery of the frame and is corrected by aperture, and astigmatism is throughout the entire field of the frame, except for the center and at all values of the aperture. Below the crop area is from the center (left image) and corner (right image).
At 24 mm, astigmatism is not observed. Coma appears at f/4-5.6, however, its level is not significant. Thus, even at the widest aperture, the Canon RF 24-105/4 lens can be successfully used in scenes where small points of light are present.
At a focal length of 105 mm, neither coma nor astigmatism appears.
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It would be foolish to expect beautiful bokeh from a kit lens with this focal length range and f / 4 aperture, but let’s analyze the nature of the blur.
24mm: The light discs are small, but their shape has a near perfect circle at f / 4-8, which is slightly distorted towards the edge of the frame. The blur character is very pleasing for such a wide angle. This should be especially appreciated by videographers, because 24 mm is a rather popular focal length for video shooting.
105mm: But the focal length of 105 mm is already applicable in portrait photography. As you can see, you can get pretty nice blur at the widest aperture. The light discs are almost uniformly filled with only subtle edging. Overall, the blur for such a versatile lens is very nice.
Canon says the new 24-105 / 4 lens is equipped with optical image stabilization, which is capable of achieving efficiency up to 5 stops. Let me remind you that a similar lens for the old EF mount had one stop efficiency.
The stabilization efficiency test was carried out on a kind of “ophthalmic table” of 10 lines. At each exposure, 10 frames were created, holding the camera in hands, then the sharp lines were counted and the percentage of efficiency for each exposure was displayed. 70 percent is considered the threshold.
For 24mm, the optical stabilizer is 4 1/3 stops effective in our testing. Moreover, the efficiency of the stabilizer when the shutter speed is reduced to one stage is 100 percent.
Surprisingly, the stabilizer was more effective at 105mm. Judge for yourself, according to the test results, the effectiveness was up to 5 2/3 steps. This is a very cool figure for an optical stabilizer.
The lens has a Nano USM ultrasonic drive. Works smartly, the main thing is not to “trick” in the settings. The camera allows you to set the autofocus speed from -7 to +2. Below are tests of autofocus operation at different speed settings: standard, -7 and +2, respectively. In the background, the motor of the cooler of the LED device is noisy, which, of course, makes it difficult to make out the noise of the motor, however, it is noticeable when the autofocus is operating at maximum speed of +2. The sound was recorded on in-camera microphones.
Canon RF 24-105mm F4L IS USM for Video
On the whole, some aspects analyzed in the tests above also apply to the quality of the video image. However, since we are shooting with a camera, let’s dive a little deeper into the quality of a video lens.
When you switch to video mode, the 9-blade aperture begins to switch smoothly, not in jumps. Moreover, regardless of the speed of rotation of the control wheel, the diaphragm closes and opens at the same speed.
We have already talked about the stabilizer in the context of the photo, but still, let’s analyze its work in video shooting.
The gimbal does a great job. It should be noted that during the shooting I did not try to soften my gait and there was no weighting body kit. The Canon EOS R camera has additional digital stabilization. Let’s see how it works in conjunction with an optical stabilizer:
The double gain of the electronic stabilizer is not applicable for shooting while walking, so the picture turned out to be appropriate.
The Canon RF 24-105mm F4L IS USM lens, as I wrote above, has a fairly compact size and light weight. Another important indicator for a videographer is focus breathing – changing the scale of the image when refocusing. Given that this is a versatile zoom, focus breathing is very minimal at just 1.5 percent.
A more serious indicator is varifocality or parfocality. The lens’ ability to maintain focusing distance across focal lengths is only common with very expensive cinema lenses. Here we see a change in distance by about one and a half centimeters, which, given the large range of focal lengths, is just an excellent result.
The big lens is a special direction. This lens usually goes through the hands of every photographer. We all start somewhere and this is unlikely to be an expensive high-aperture lens. But more experienced photographers in 90 percent of cases will advise you to overpay and immediately take a “normal” lens. Why? In history, big lenses have never been of high image quality. However, the transition of manufacturers to mirrorless systems and improved conditions for the production of high-quality lenses in the form of a new mount, in my opinion, will change this practice. Canon’s new RF 24-105mm F4L IS USM lens is amazing!
Judge for yourself. It is a versatile constant aperture lens. Beautiful bokeh at 105mm. Minimal vignetting, excellent glare protection, fast and quiet operation of the autofocus motor, powerful optical stabilizer, slight coma at a wide angle. Sharpness, although it requires comments on the periphery, but in general it is higher than that of its predecessors. Strong lateral chromatic aberrations are certainly a disadvantage, but the correction of this kind of distortion in any editor is automatic and does not take much time.
And most importantly, the cost of this lens has remained at the same level as the cost of its predecessor for the EF mount. Of course, to make this possible, we had to sacrifice a bit of body materials. Canon RF 24-105mm F4L IS USM is assembled with high quality, the mount looks reliable, there is protection from dust and moisture, but the plastic of the case raises questions. It feels very thin and is prone to scratches. However, the Canon RF 24-105mm F4L IS USM takes lens image quality to a whole new level.
And further. Modern cameras are now part-time advanced video cameras. Canon RF 24-105mm F4L IS USM is ready to support this trend. First, it is again a constant aperture and a wide range of focal lengths. Secondly – absolutely minimal focus breathing, step less aperture adjustment and quiet autofocus. Oh yes, and also compact size, allowing you to mount the camera with a lens on a gimbal. I can safely say that the Canon RF 24-105mm F4L IS USM will be an excellent choice not only for photography, but also for video shooting.