Canon RF 24-240mm F4-6.3 IS USM Lens Review

The first eye-catching attribute of the Canon RF 24-240mm F4-6.3 IS USM Lens lies right in the product name. The 10x 24-240mm focal length range in a single lens is simply awesome, ready to ideally frame a very significant percentage of opportunities availed. That this lens also provides high-performing image stabilization, has also-high-performing Nano USM AF, and has a nice, relatively compact design while bearing an entry-level price tag is equally awesome.

My standard reaction to a lens featuring a long focal length range, 10x in this case, is to question the image quality it delivers. As always, we'll discuss image quality in depth in this review and while most of us place a very high value on image quality, image quality is not everything. For example, you are using the RF 24-240mm lens while your friend has chosen a 24-70mm lens because he/she argues that it delivers better image quality. Then a fleeting 200mm opportunity shows up. Perhaps an eagle carrying a bright red salmon lands 30' (10m) in front of you in perfect light. You immediately capture the first shot before your friend has his 24-70mm lens removed. You continue to capture half a dozen great images along with the eagle taking off with the fish still in its talons and the opportunity is gone before your friend has his 70-200mm lens mounted. In this case, the 24-240mm lens delivered much better image quality than the 24-70mm lens.

Fun is another factor that plays into this discussion. Most of us define photography as fun. However, few of us find it fun to change lenses (some of us even cringe about the potential for imaging sensor dust being acquired during this task) and few of us find it fun to physically carry lenses we're not using. Most of us do find it fun to go out with a single lens and be able to photograph a wide range of scenarios.

This lens has a lot of convenience and fun built into it. This is a superb travel lens. This is a great lens for video recording. This lens is great for a less-seriously-photographing spouse or child. There are a lot of additional reasons to acquire the Canon RF 24-240mm F4-6.3 IS USM Lens.

All Canon RF mount lenses require a Canon EOS R-series camera behind them. The Canon RF lens series provides a significant number of reasons to desire one of these cameras.

Canon RF 24-240mm F4-6.3 IS USM Lens Top View with Hood

Focal Length Range

At the top of the lens selection funnel is the focal length range needed for the task at hand. The right focal length provides the ideal working distance and perspective for the composition to be captured. This lens' huge 10x focal length range, covering a range otherwise requiring at least 2 zoom lenses, does not narrow this selection funnel very much. This lens is suitable for an extremely long list of photography needs with ideal perspectives able to be covered in a large percentage of encountered scenarios.

At this moment, it seems easier to list what uses these focal lengths are not optimal for. With the ultra-wide-angles missing, interior architecture and some landscape uses may require a panorama technique when using 24mm. This lens will likely be found short for large field sports with significant cropping needed from 240mm captures. The 240mm full frame focal length is only marginally useful for wildlife photography, though large and/or close animals are fair game for this range. Your pets likely qualify.

Canon RF 24-240mm F4-6.3 IS USM Lens Old Blue Truck Sample Picture

The 24-240mm focal length range is especially superb for family and travel needs. I carried this lens on several of my workshops. One use that I found was at a car show I visited in Estes Park during some time between my Rocky Mountain National Park workshops (I was homeless for an afternoon).

Canon RF 24-240mm F4-6.3 IS USM Lens Old Red Car Sample Picture

This lens and the color it captured during that event was very entertaining.

Canon RF 24-240mm F4-6.3 IS USM Lens Old Purple Car Sample Picture

I could zoom out and capture the entire vehicle or zoom in for details void of people.

Canon RF 24-240mm F4-6.3 IS USM Lens Focal Length Range Example

That amazing grill is on the front of a 1942 Chevrolet truck. Below is the back end of a sweet Ford Shelby GT500, the view you are likely to have when on the track when racing against it.

Canon RF 24-240mm F4-6.3 IS USM Lens Ford Shelby Cobra GT500 Sample Picture

This lens was equally entertaining in the harbors near Acadia National Park.

Canon RF 24-240mm F4-6.3 IS USM Lens Boat Sample Picture

It also worked great inland at locations such as the Sommesville Bridge.

Canon RF 24-240mm F4-6.3 IS USM Lens Bridge Sample Picture

When you don't know what focal lengths will be needed, the odds are great that this lens has them covered.

Canon RF 24-240mm F4-6.3 IS USM Lens Front View

Max Aperture

The f/4-6.3 in the name refers to the maximum aperture, the ratio of the focal length to the diameter of the entrance pupil, available in this lens. Wider apertures (lower numbers) are always better to have available — until the price, size, and weight penalties are factored in. Want a long focal length range that includes telephoto lengths in a zoom lens without a large size, heavy weight, and high price? You are likely looking at a variable max aperture lens and the apertures in the variable range will not be too wide. That is what we have in the Canon RF 24-240mm F4-6.3 IS USM Lens.

Here is this lens' max aperture step down by focal length:

24-26mm = f/4.0
27-43mm = f/4.5
44-69mm = f/5.0
70-104mm = f/5.6
105-240mm = f/6.3

At 24mm, the f/4 aperture is reasonably wide (though few 24mm lenses do not open to at least f/4). Unfortunately, f/4 is only available for a very short 3mm range. At 240mm, we have the narrowest max aperture found in a Canon EF or RF full frame lens. With these max apertures, this lens is not a good choice for low light action such as indoor sports without flash (as a main light/overpowering ambient light) being involved. Those following the "f/8 and be there" rule and those photographing outdoors during daylight will have the necessary apertures available. When recording video, only 1/60 second shutter speeds (twice filming framerate) are typically needed (assuming you’re not capturing high framerate slow-motion video) and wide apertures are not often required for 1/60 second rates in normally encountered ambient lighting.

A downside to the variable max aperture is that, by definition, the same max aperture cannot be used over the entire focal length selected. The camera automatically accounts for the changes when in auto exposure modes, but making use of the widest-available aperture in manual exposure mode is complicated somewhat by the changing setting.

An advantage held by wide apertures is their ability to strongly blur the background. This lens does not have those, but it has the other background blur advantage: long focal lengths. Following are examples of the maximum background blur this lens can produce:

Canon RF 24-240mm F4-6.3 IS USM Lens Maximum Blur Example

While the 24mm example does not show the background being erased, the 240mm result does.

Canon RF 24-240mm F4-6.3 IS USM Lens Angle View

Image Stabilization

While image stabilization systems do not help stop subject motion, they provide a remarkable improvement for handheld image sharpness with stationary subjects, making up for some of the narrow aperture shortcomings. Canon's RF lens image stabilization systems have been proving impressive. Add this one to that list.

Unless I am using a camera support, I seldom leave home without IS and I often regret those times when I do. Image stabilization allows handholding of the camera in extremely low light situations with still subjects (or permits motion blurring of subjects with sharp surroundings such as flowing water). The image quality difference made by IS is potentially dramatic.

One situation that I am frequently counting on IS for assistance with is when handholding in medium and low light levels when significant depth of field is needed, allowing narrower aperture use without a tripod. When using a circular polarizer filter with narrow apertures (typical for landscapes and cityscapes), IS can be helpful even under direct sunlight, especially at the longer focal lengths.

IS is useful for stabilizing the viewfinder, aiding in optimal composition (though not as big of an issue with wide-angle focal lengths). IS is also very useful for stabilizing video recording and directly related is that "The RF 24-240mm F4-6.3 IS USM lens is the first Canon lens that features Dynamic IS for full-frame cameras." [Canon USA] Dynamic IS aids in stabilizing video recording while the camera is in motion.

This IS system is practically silent with only a faint "hmmm" heard while active with an ear against the lens. Canon's IS systems have long been very well behaved, referring to the viewfinder image always being stable and I do not find myself fighting against IS while recomposing or recording video. I have not noticed the image framing drifting while IS is active unless a position change was just made.

In addition to general refinements, this lens gets a very-high 5-stops of assistance rating. Improved communications between the lens and the camera via the new RF mount has made this impressive rating possible. For example, based on this rating, an ISO setting 5 stops higher, ISO 3200 instead of ISO 100 or ISO 25600 instead of ISO 800, for example, would be necessary to increase the shutter speed enough to compensate for the help provided by this system. That difference is huge in terms of image quality.

At 24mm, most images captured at 0.6-seconds were sharp, the sharp-to-blurred image ratio was still positive at 0.8-seconds, and a significant percentage of 1.0-second captures were sharp. At 240mm, most images were sharp at 1/15 seconds and there were more sharp than blurred results at 1/10 second shutter speeds. The rate of sharp image capture slowly decreased as exposure times increased with a number of presentable images captured at 0.3-seconds.

These numbers should be considered about the best I can do. While I'm not the steadiest photographer, this testing is done under ideal conditions, indoors on a concrete floor. Quickly hike up a big mountain and shoot from an unstable position in strong winds and a significantly faster shutter speed is going to be needed. However, the amount of assistance should remain similar and that is very important.

When you need/want to leave the tripod behind, including for travel and family events, IS is there for you, helping to ensure sharp images and adding significant versatility to this lens.

Canon RF 24-240mm F4-6.3 IS USM Lens on Tripod

Image Quality

I mentioned being concerned about the image quality of a superzoom lens. There are sacrifices required to design an overall superzoom lens package such as this one (otherwise, all lenses would be superzooms) and image quality typically suffers at least somewhat. Still, the lenses being developed for the RF mount thus far have been incredible and that gave me optimism in this regard.

Canon RF 24-240mm F4-6.3 IS USM Lens MTF Chart

The MTF charts were half not bad. However, half of those lines trailing downward rapidly away from their pairs off-center provided some evidence to affirm my original expectations.

At 24mm, this lens turns in impressive center-of-the-frame results even at its wide-open aperture and the wide-open 50mm results are similar. By 100mm, slight softening can be noticed and 240mm wide-open results are somewhat soft in the center.

In general, lenses are not as sharp at their wide-open apertures as they are when stopped down one or two stops. In the center-of-the-frame, 24mm wide-open image quality needs no improvement and it gets very little at f/8. The other focal lengths gain similarly little image quality at narrow apertures. From a center-of-the-frame perspective, use the aperture that provides the right amount of light and depth of field for the shot.

In general, lenses are not as sharp in the periphery where light rays must be bent more strongly than they are in the center. This lens' 24mm corners have decent image quality, especially related to distortion and lateral CA issues, both of which I'll talk about in more depth later on. Corner image quality at 50mm and 100mm is very good, impressively so for such a lens. Lateral CA is back in a big way in the 240mm corners and again, I'll share more in this regard.

Don't expect much corner improvement from stopping down (and there is not much room for stopping down at the long end prior to bumping into the softening effects of diffraction).

Taking the testing outdoors, we next look at a series of center-of-the-frame 100% resolution crop examples. These images were captured using a Canon EOS R with RAW files processed in Canon's Digital Photo Professional using the Standard Picture Style and sharpness set to "2" on a 0-10 scale (note that even modestly-high sharpness settings are destructive to image details and hide the true characteristics of a lens).

Canon RF 24-240mm F4-6.3 IS USM Lens Sharpness Comparison Example

24mm: f/4.0 | f/5.6 | f/8.0   50mm: f/5.0 | f/5.6 | f/8.0
100mm: f/5.6 | f/8.0   240mm: f/6.3 | f/8.0

Be sure to find details in the plane of sharp focus for basing your assessment.

In some lens designs, the plane of sharp focus can move forward or backward as a narrower aperture is selected. This is called focus shift (residual spherical aberration, or RSA), it is seldom (never?) desired, and this lens does not exhibit such.

Next, we'll look at a comparison showing 100% extreme-top-left-corner crops captured and processed identically to the above center-of-the-frame images. These images were manually focused in the corner of the frame.

Canon RF 24-240mm F4-6.3 IS USM Lens Corner Sharpness Comparison Example

24mm: f/4.0 | f/5.6 | f/8.0   f/4.0 | f/5.6 | f/8.0
50mm: f/5.0 | f/5.6 | f/8.0   100mm: f/5.6 | f/8.0
240mm: f/6.3 | f/8.0   f/6.3 | f/8.0

The second set of 24mm and 240mm corner crops feature lateral CA correction applied. I've often mentioned that this lens aberration is easy to correct with the right software and lens profile and the correction shown here was applied with the check of a box. Click and done. While the results of those two focal length corners are not perfect after the correction was applied, they definitely look better.

Does corner sharpness matter? Sometimes it does, sometimes it doesn't. Landscape photography is one photographic discipline that presents frequent scenarios requiring sharp corners. Portrait photography usually does not require them. Videos captured at normal wide-aspect ratios also avoid use of the corners.

The physical properties of light passing through a lens make it impossible for the same amount of light to reach the edges of the circle as the center, resulting in a darkening of the corners, referred to as vignetting or peripheral shading. When used on a camera that utilizes a lens' entire image circle, peripheral shading can be expected at the widest aperture settings. This lens shows a moderate 3-stops of shading at 24mm f/4 and at 240mm f/6.3. The 50mm f/5 focal length and aperture combination show only about 1.6-stops of shading, a relatively low amount for any wide-open aperture. The 100mm f/5.6 results show about 2-stops of corner shading.

Stopping down the aperture to f/8 decreases peripheral shading where the amount stabilizes to about 1.5-stops of shading in the 24mm corners, an amount sometimes noticeable. As the lens focal length increases at f/8, corner shading reduces to about 1-stop at 50mm and to about 0.6-0.8-stops remains in the longer focal length range corners at f/16.

Vignetting can be corrected during post processing with increased noise in the brightened areas being the penalty or it can be embraced, using the effect to draw the viewer's eye to the center-of-the-frame.

The effect of different colors of the spectrum being magnified differently is referred to as lateral (or transverse) CA (Chromatic Aberration). Lateral CA shows as color fringing along lines of strong contrast running tangential (meridional, right angles to radii) with the mid and especially the periphery of the image circle showing the greatest amount as this is where the greatest difference in the magnification of wavelengths typically exists.

Any color misalignment present can easily be seen in the site's image quality tool, but let's also look at a set of worst-case examples, 100% crops from the extreme top left corner of EOS R frames showing diagonal black and white lines.

Canon RF 24-240mm F4-6.3 IS USM Lens Lateral Chromatic Aberration Example

There should be only black and white colors in these images and the additional colors are showing the presence of lateral CA.

With the right lens profile and software, lateral CA is often easily correctable (often in the camera) by radially shifting the colors to coincide (though it is always better to not have the problem in the first place). The two "C" results shared above have lateral CA correction applied via a simple checkbox in DPP. While the corrections are not absolutely perfect, the differences are impressive, aren't they? Without correction, the amount of lateral CA present at both ends of the focal length range is rather extreme. The 50mm results show some lateral CA and the color shift crossover (colors aligning and then reversing) happens at around 100mm where little color shift is seen.

A relatively common lens aberration is axial (longitudinal, bokeh) CA, which causes non-coinciding focal planes of the various wavelengths of light, or more simply, different colors of light are focused to different depths. Spherical aberration along with spherochromatism, or a change in the amount of spherical aberration with respect to color (looks quite similar to axial chromatic aberration but is hazier) are other common lens aberrations to look for. Axial CA remains at least somewhat persistent when stopping down with the color misalignment effect increasing with defocusing while the spherical aberration color halo shows little size change as the lens is defocused and stopping down one to two stops generally removes this aberration.

In the real world, lens defects do not exist in isolation with spherical aberration and spherochromatism generally found, at least to some degree, along with axial CA. These combine to create a less sharp, hazy-appearing image quality at the widest apertures.

In the examples below, look at the fringing colors in the out of focus specular highlights created by the neutrally-colored subjects. Any color difference is being introduced by the lens.

Canon RF 24-240mm F4-6.3 IS USM Lens Spherical and Axial Aberration Example

It is not unusual for a narrow aperture lens to emerge relatively unscathed by this test and these results are showing very little color misalignment, mostly only at 240mm.

Flare is caused by bright light reflecting off of the surfaces of lens elements, resulting in reduced contrast and sometimes-interesting artifacts. The shape, intensity, and position of the flare in an image is variable and depends on the position and nature of the light source (or sources) as well as on the selected aperture, shape of the aperture blades and quality of the lens elements and their coatings. Our standard flare testing uses the sun in the corner of the frame and most lenses show noticeable flaring, especially at narrow apertures, in this test. Despite the relatively high 21/15 element/group count, the RF 24-240mm lens performs admirably in this regard at wide-open apertures and at 24mm f/16. Longer focal length results were OK at f/16.

Flare effects can be embraced, avoided, or removal can be attempted. Removal is sometimes very challenging and, in some cases, flare effects can be quite destructive to image quality.

There are two lens aberrations that are particularly evident when shooting images of stars, mainly because bright points of light against a dark background make them easier to see. Coma occurs when light rays from a point of light spread out from that point, instead of being refocused as a point on the sensor. Coma is absent in the center-of-the-frame, gets worse toward the edges/corners, and generally appears as a comet-like or triangular tail of light which can be oriented either away from the center-of-the-frame (external coma), or toward the center-of-the-frame (internal coma). Astigmatism is seen as points of light spreading into a line, either meridional (radiating from the center of the image) or sagittal (perpendicular to meridional). Remember that lateral CA is another aberration apparent in the corners.

The images below are 100% crops taken from the extreme top-left corner of EOS R frames.

Canon RF 24-240mm F4-6.3 IS USM Lens Coma Example

The 50mm results are impressive and the 100mm results are my next favorite. The 24mm results are not terrible (all things considered) and the 240mm results are showing some stretching.

This is a standard zoom lens and the standard zoom lens geometric distortion statement holds true. The RF 24-240mm lens has barrel distortion at the wide end that transitions into negligible distortion and on into pincushion distortion at the long end. However, that is where this review takes a tangent. A very low amount of distortion is what you will see in the viewfinder (lens distortion correction is always on), in JPG results, and in RAW file results from images that are processed using an app with the proper lens aberration profile loaded. However, this lens' native amount of distortion is extreme.

Rudy Winston, Canon U.S.A shares:

"Distortion correction is nothing new in digital imaging, of course – we’ve seen it both in-camera, and certainly in software, for some time."

"Usually, it’s done to minimize typical levels of either barrel or pincushion distortion. While many lenses nowadays are designed to allow some of either to creep in – with the assumption that in today’s digital world, it’ll be correctible for critical users – normally, the levels of UNCORRECTED distortion are still within what at least casual viewers would consider “acceptable.”

"However, with the RF 24-240mm lens, to get the 10x zooming, size and weight, full-frame coverage, and good levels of overall sharpness into a package that sells for under $1,000, apparently (and this is ME speaking – not a formal comment from either Canon or the Lens Development Group in Japan), the decision was made to allow very extreme levels of distortion to occur at the 24mm position, and to apply correction via detailed Lens Profiles either in-camera or (for RAW images) at the computer. And, I’m told that Canon worked aggressively with Adobe to be sure to have the right profiles available to customers using Lightroom or ACR as soon as possible."

"Anyhow, consider it a very strong form of distortion correction. Using an older version of something like ACR/Lightroom, if you shoot a RAW file and view it within that software, files shot at or near 24mm with this lens will look almost like a terrible imitation of a fisheye lens, complete with hopeless vignetting and so on. So it’s apparent that the lens profiles REALLY make a difference here. It’s no accident that when the lens is attached to the EOS R or RP cameras, that Distortion Correction is always on, and grayed-out (you cannot turn it off, in-camera)."

Brace yourself. We're going to look behind the curtains and this is going to be painful. Here are the uncorrected test results from our standard distortion test (captured at f/8).

Canon RF 24-240mm F4-6.3 IS USM Lens Distortion Example

Distortion correction is destructive at the pixel level as image details must be stretched using computational algorithms to determine what the newly-created details should be. Since such correction is required when using this lens, I suggest removing the distortion factor from your selection criteria. Consider this lens to have very low amounts of geometric distortion and use the resulting image quality as the big deciding factor for or against this lens. Considering the amount of correction required in the 24mm corners, the resulting image quality is remarkably good.

Note that this lens' corrected wide-angle focal length appears to be 24mm as stated (based on our distance-to-chart measurements), meaning that the true focal length, prior to distortion correction, is likely considerably wider than 24mm. Process your 24mm RAW images using software that does not force distortion correction for a fisheye look.

The blur and quality of blur seen in the out of focus portions of an image are referred to as bokeh. The amount of blur a lens can produce is easy to show (and was shown earlier in the review). Assessing the quality is a much harder challenge due in part to the number of variables present in any scene.

The following are f/11 examples of out-of-focus specular highlights along with some outdoor examples.

Canon RF 24-240mm F4-6.3 IS USM Lens Bokeh Example

These results, especially at the longer focal lengths, look nice to me. With the aperture blades not closing so far to create f/11 at 240mm, though shapes retain an especially strong circular shape.

The cat's eye bokeh effect, a form of mechanical vignetting appearing in the wide-open aperture corners, is shown in the next set of samples. If you look through a tube at an angle, similar to the light reaching the corner of the imaging sensor, the shape is not round and that is the shape seen here. As the aperture narrows, the entrance pupil size is reduced and the mechanical vignetting absolves with the peripheral shapes becoming round. Note that the 24mm example shows 1/4 of the frame cropped from the top-left corner.

Canon RF 24-240mm F4-6.3 IS USM Lens Cat's Eye Bokeh Example

With an odd-numbered aperture blade count (7), point light sources captured with a narrow aperture and showing a star-like effect will have twice as many points as aperture blades (14). The best starburst effects tend to be produced by wide aperture lenses. This is not one of those, though the 24mm focal length can produce a very nice star at f/22.

Canon RF 24-240mm F4-6.3 IS USM Lens 24mm Starburst Effect Example

The longer focal lengths with their narrower max apertures produce a rather ugly effect at the same aperture. A 240mm example is shown below.

Canon RF 24-240mm F4-6.3 IS USM Lens 240mm Starburst Effect Example

This is not the best lens choice if the starburst effect is desired at long focal lengths, though f/38 may produce a better result (from only this perspective).

Canon RF 24-240mm F4-6.3 IS USM Lens Design

Overall, this lens is not producing the best image quality available. However, image quality is only part of the lens selection decision. That this lens produces this level of image quality despite the huge overall focal length range is a positive trait.

Canon RF 24-240mm F4-6.3 IS USM Lens Angle View Extended with Hood

Focusing

Canon has implemented their latest high-performing Nano USM (Ultrasonic Motor) driven AF system in this lens.

Nano USM acts like an ultra-fast version of STM AF, combining the benefits of a high-speed Ring USM actuator with an STM system stepping motor's quiet and smooth, direct, lead screw-type drive system. Like Ring USM driven AF systems, Nano USM focuses extremely fast – nearly instantly. Like STM AF systems, Nano USM focuses almost silently, with only faint clicking heard with one's ear next to the lens. And, Nano USM lenses focus very smoothly.

Canon RF 15-35mm F2.8 L IS USM Lens Nano USM

Canon U.S.A.'s Rudy Winston states: "Canon’s new Nano USM technology uses a completely different form factor, but achieves focus results within the lens via the same principles of ultrasonic vibration energy, transmitted here into linear (rather than rotational) movement within the lens. This tiny new Ultrasonic motor achieves the combination of fast, near-instant response during still image shooting, with the smoothness required for good focus during video recording."

While Ring USM has been Canon's preference for high-end lens designs, these lenses do not generally focus so smoothly in Movie Servo AF. While the review-time-latest Canon DSLRs are able to focus a Ring USM lens with good smoothness, these lenses still do not compare to the smoothness of STM lenses and there is considerably more focus chatter sound during Movie Servo AF.

Of ultimate importance is AF accuracy and from that perspective, this lens (and all of Canon's RF lenses to date) performed impressively.

Canon RF 24-240mm F4-6.3 IS USM Lens Extended Top View with Hood

A first for a Canon RF lens is that the control ring serves dual purposes, acting also as a manual focus ring with a switch toggling the functionality. From a focus ring perspective, this knurled plastic ring is mid-sized and positioned behind the zoom ring. This position is not my favorite and with the lens' balance point being located here, there is a risk of inadvertent changes being made by the hand holding the lens.

Like STM, Nano USM utilizes a focus-by-wire or electrical manual focus design (vs. a direct gear-driven system). The manual focus ring electronically controls the focus of the lens. FTM (Full Time Manual) focusing is supported in AF mode with the camera in One Shot Drive Mode, but the shutter release must be half-pressed for the focus ring to become active (Lens electronic MF after One Shot focusing must be enabled). Note that FTM does not work if electronic manual focusing after One Shot AF is disabled in the camera's menu. The lens' switch must be in the "MF" position and the camera meter must be on/awake for conventional manual focusing to be available.

With electronics driving AF, the rate of focus change caused by the focus ring can be electronically controlled and it can be variable, based on the ring's rotation speed. I never acclimated to that feature and with the R-series cameras, a linear adjustment speed can be configured. That's my preference and in this mode, the RF 24-240's focus is adjusted very slowly, with approximately 390° of ring rotation from MFD to infinity, for very precise focusing capabilities.

The manual focus ring has an ideal resistance and adjustments are smooth and solidly centered with no unusual framing shift happening.

Modest subject magnification/framing changes are seen in full extent focus range changes ("D" references "Distant" and "C" represents "Close").

Canon RF 24-240mm F4-6.3 IS USM Lens Focus Magnification Example

24mm: D | C   50mm: D | C   100mm: D | C   240mm: D | C

The review lens does not maintain the proper focus distance throughout the entire zoom range (it is not parfocal). You will want to refocus after changing focal lengths. However, the proper focus distance is in general closely maintained, either naturally through design or perhaps via electronic adjustment.

Cameras featuring Dual Pixel CMOS AF and Movie Servo AF make video recording very easy and Nano STM lenses are very well-suited for this task. The smooth focusing makes focus distance transitions easy on the viewer's eyes and the sound of focusing is barely audible. The lens' aperture changes are also quiet and smooth.

No focus distance scale is provided on the lens, but a digital scale can be enabled in the electronic viewfinder or rear LCD.

The RF 24-240 has a specified minimum focus distance of 19.69" (500mm) and a very strong 0.26x maximum magnification capability. This lens has no direct equivalent for comparisons, so I'll select a small handful of lenses for this table and let you use the site's tools to create comparisons relevant to you.

ModelMFDMM
Canon EF-S 18-200mm f/3.5-5.6 IS Lens17.7"(450mm)0.24x
Canon RF 24-105mm F4 L IS USM Lens17.7"(450mm)0.24x
Canon RF 24-240mm F4-6.3 IS USM Lens19.7"(500mm)0.26x
Canon EF 28-300mm f/3.5-5.6L IS USM Lens27.6"(700mm)0.30x
Tamron 28-300mm f/3.5-6.3 Di VC PZD Lens19.3"(490mm)0.29x

While this lens has a single specified minimum focus distance and maximum magnification value, our tests show that this lens focuses significantly closer at wider angles than at longer angles. Our measured minimum focus distance range was 14.53 and 30.12" (369 and 765mm) for 24mm and 240mm respectively. At 24mm, a subject measuring approximately 12.5 x 8.3" (318 x 211mm) will fill the frame at the minimum focus distance and the numbers are 4.8 x 3.2" (122 x 81mm) for 240mm.

Need a shorter minimum focus distance and greater magnification? An extension tube mounted behind this lens should provide improvements ranging from strong to modest over the focal length range. Extension tubes are hollow lens barrels that shift a lens farther from the camera, which permits shorter focusing distances at the expense of long-distance focusing. Electronic connections in extension tubes permit the lens and camera to communicate and otherwise function as normal. As of review time, Canon does not have RF mount-compatible extension tubes available, but third-party options are becoming available.

This lens is not compatible with Canon extenders.

Canon RF 24-240mm F4-6.3 IS USM Lens Extended Top View

Build Quality & Features

Now we know what non-L RF series lenses will, at least initially, look like as the 24-240mm F4-6.3 IS USM Lens is the first non-L zoom model in the Canon RF lineup. Externally, aside from the missing red ring, this lens looks and functions a lot like its L counterparts.

This lens looks very nice and the fit and finish of construction are excellent.

Canon RF 24-240mm F4-6.3 IS USM Lens Product Images

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With smooth external dimensions and tight tolerance between parts, the Canon RF 24-240mm F4-6.3 IS USM Lens is very comfortable to hold and a pleasure to use.

The ribbed rubber-coated zoom ring is large, easy to find and smooth in function. As mentioned, I'm not a fan of the forward-mounted zoom ring design.

Also as mentioned, the knurled "Control Ring" is provided and able to be configured for fast access to settings including aperture, ISO, and exposure compensation. At the throw of a switch, the control ring becomes the focus ring. Both cannot be used at the same time, but there is one less ring to become confused with. Likely is that a majority of the people who buy this lens will seldom (never?) use manual focus. Note that this control ring is smooth, not clicked as is often the current default for the L variants.

This lens features a quality plastic external construction.

Canon RF 24-240mm F4-6.3 IS USM Lens Angle Extended View

As illustrated in some of the product images shared in this review, this lens extends significantly (2.78" / 70.7mm) when zoomed to 240mm. The extended inner lens barrel has especially little play for the amount of extension. An extension lock switch is provided and was not needed on the new test lens.

Canon RF 24-240mm F4-6.3 IS USM Lens Side View

The FOCUS/CONTROL and IS switches are flush-mounted and low-profile, but raised just enough for easy use, even with gloves. They snap crisply into place.

Canon RF 24-240mm F4-6.3 IS USM Lens Mount

This lens is not weather-sealed. Use caution when in potentially dusty and/or wet environments.

Unlike the RF L lenses, the RF 24-240mm lens lacks the fluorine coatings on the front and rear lens elements that avoid adhesion of dust and liquids and to make cleaning easier. The fluorine-coated lenses are noticeably easier to clean.

At 3.2 x 4.8" (80.4 x 122.5) in size, I consider this a medium-sized lens and at 26.5 oz (750g), this lens is a touch above what most would consider light. Still, it is not too large or heavy to carry even for long periods of time and many miles. I've hiked a lot of miles with this lens in my pack and in my hand and carrying this single lens is a better option than carrying any near-equivalent combination of multiple lenses.

ModelWeight oz(g)Dimensions w/o Hood "(mm)FilterYear 
Canon EF-S 18-200mm f/3.5-5.6 IS Lens21.0(595)3.1 x 4.0(78.6 x 102.0)722008
Canon RF 24-105mm F4 L IS USM Lens24.7(700)3.3 x 4.2(83.5 x 107.3)772018
Canon RF 24-240mm F4-6.3 IS USM Lens26.5(750)3.2 x 4.8(80.4 x 122.5)722019
Canon EF 28-300mm f/3.5-5.6L IS USM Lens59.0(1670)3.6 x 7.6(92.0 x 194.0)772004
Tamron 28-300mm f/3.5-6.3 Di VC PZD Lens19.1(540)2.9 x 3.8(74.4 x 96.0)672014

For many more comparisons, review the complete Canon RF 24-240mm F4-6.3 IS USM Lens Specifications using the site's Lens Spec tool.

Here is a visual comparison of a subset of the above list:

Canon RF 24-240mm F4-6.3 IS USM Lens Compared to Similar Lenses

Positioned above from left to right are the following lenses:

Canon RF 24-105mm F4 L IS USM Lens
Canon RF 24-240mm F4-6.3 IS USM Lens
Canon EF 28-300mm f/3.5-5.6L IS USM Lens

Retracted, the 24-200 is not much larger than the 24-105 and it is dwarfed by the 28-300. The same lenses are shown below extended with their hoods in place.

Canon RF 24-240mm F4-6.3 IS USM Lens Compared to Similar Lenses with Hoods

Use the site's product image comparison tool to visually compare the Canon RF 24-240mm F4-6.3 IS USM Lens to other lenses. I preloaded that link with another comparison.

This lens utilizes 72mm threaded filters. These are mid-sized threads resulting in mid-sized filters with mid-sized costs. That this size is rather common is also positive. A slim circular polarizer filter model such as the Breakthrough Photography X4 is recommended for this lens.

Canon RF 24-240mm F4-6.3 IS USM Lens Side View with Hood

It is not an L lens and Canon is still not providing lens hoods in the non-L lens boxes. The Canon EW-78F Lens Hood is optional (and somewhat expensive for what it is). This is a semi-rigid plastic petal-shaped hood with a matte plastic interior designed to avoid reflections. A petal-shaped hood is easier to align for installation (simply learn the petal orientation) while a rounded hood enables the lens to stand on its hood. A push-button release makes the bayonet mount very easy to use (little friction). This hood offers a good amount of protection, from both impact and, primarily at the wide focal lengths it must accommodate, from bright light.

No lens case is included in the box, but finding a case for a common lens form factor is not challenging. Lowepro's Lens Cases get my vote as very nice and affordable solutions for single-lens storage, transport, and carry.

Canon RF 24-240mm F4-6.3 IS USM Lens Cap

Canon does not offer a USB dock accessory for their lenses but with lens firmware being updatable via the camera, there is little reason to need an accessory dock. Lens caps are a very-frequently-used accessory that is included and Canon's current lens cap models are great.

Canon RF 24-240mm F4-6.3 IS USM Lens Front View on Camera

Price and Value

The Canon RF 24-240mm F4-6.3 IS USM Lens has a mid-level price among lenses in general. That is, of course, if you view it as a single lens. Since this lens can, for some uses including travel, take the place of multiple lenses, the overall cost seems quite reasonable. Being priced less than half as much as the recently released L-series RF lenses makes this lens seem especially affordable.

As an "RF" lens, the Canon RF 24-240mm F4-6.3 IS USM Lens is compatible with all Canon EOS R series cameras. Canon USA provides a 1-year limited warranty.

The reviewed Canon RF 24-240mm F4-6.3 IS USM Lens was online-retail sourced.

Canon RF 24-240mm F4-6.3 IS USM Lens Angle View with Hood

Alternatives to the Canon RF 24-240mm F4-6.3 IS USM Lens

At review time, this lens does not have an equal and there are very few full frame super zoom lenses to even consider for comparison. Note that the lenses I am going to talk about below do not have the strong distortion with mandatory correction that the RF 24-200 has and since the distortion for all of these lenses can also be corrected, I'll leave that aberration out of the discussions.

Perhaps the most obvious comparison is against the Canon EF 28-300mm f/3.5-5.6L IS USM Lens, although a Canon Mount Adapter EF-EOS R is required to mount this lens to an EOS R-series camera. These two lenses do not share the same focal length range and both have advantages in this regard. Having 24mm makes life a lot better for landscape photography and having 300mm available takes that lens deeper into sports and wildlife photography purposes. The EF lens has a 1/3 stop max aperture advantage in most equivalent focal length comparisons. In the image quality comparison, I like the RF lens results considerably better, especially in the periphery. The EF lens has less peripheral vignetting.

Looking at the specs and measurements, the Canon RF 24-240mm F4-6.3 IS USM Lens vs. Canon EF 28-300mm f/3.5-5.6L IS USM Lens comparison shows the huge size and weight differences with the EF lens weighing more than twice as much as the RF lens. Being a professional-grade L-series lens, the 28-300 is expected to have stronger build quality. The EF lens' filter threads are larger, 77mm vs. 72mm, and it has 8 aperture blades while the RF lens has 7 (remember that the odd count has one advantage). The EF lens has a removable tripod ring. The EF lens has the maximum magnification spec advantage, 0.30x vs. 0.26x, and the RF lens' image stabilization system is rated higher, 5-stops vs. 3-stops. Bigger than the weight difference is the price difference — the decision for many will be made by this line item alone.

At review time, the Canon RF 24-105mm F4 L IS USM Lens is probably the next most-considered RF lens for travel and general-purpose use. The focal length range comparison is not close with the 24-240 obviously having a huge advantage. The 24-105 has a fixed f/4 max aperture to its advantage. In the image quality comparison, the 24-105 has some advantages, especially in the periphery, though the differences are not as strong as one might expect. The 24-240 has less lateral CA at its midrange 100mm focal length compared to the 24-105 set to its maximum 105mm focal length.

Looking at the specs and measurements, the Canon RF 24-240mm F4-6.3 IS USM Lens vs. Canon RF 24-105mm F4 L IS USM Lens comparison shows these two lenses being similar in size though the 24-240 extends to a considerably longer length to reach its considerably longer max focal length. The 24-105 uses 77mm filters vs. 72mm. The L-lens is expected to have better build quality. While the 24-105 has a higher list price, the review time street price for this lens is the same as the 24-240.

The next lens up for discussion is the Tamron 28-300mm f/3.5-6.3 Di VC PZD Lens. Obviously, this lens shifts the focal length range longer than what the 24-240 provides. In the image quality comparison, I see the Canon lens taking an easy win. The Tamron has modestly less vignetting. Like the EF 28-300L lens, the Tamron 28-300 requires an adapter for compatibility with EOS R-series cameras.

Looking at the specs and measurements, the Canon RF 24-240mm F4-6.3 IS USM Lens vs. Tamron 28-300mm f/3.5-6.3 Di VC PZD Lens comparison shows the Tamron lens, despite reaching out to 300mm, being the lighter and smaller option, even at full extension. The Tamron has smaller filter threads, 67mm vs. 72mm, and a slightly higher maximum magnification, 0.29x vs. 0.26x. The Tamron lens' vibration compensation system does not have a rating but it is not likely as good as the Canon's newer 5-stop system. The Tamron wins this price comparison.

Use the site's comparison tools to create your own comparisons.

Canon RF 24-240mm F4-6.3 IS USM Lens Top View

Summary

The Canon RF 24-240mm F4-6.3 IS USM Superzoom Lens' headlining feature is its focal length range. The 10x zoom range makes this lens an ideal solution to a wide range of photography needs with travel perhaps being at the top of the list.

That said, this lens has a long list of other very positive features. The fast, quiet, smooth Nano USM-driven AF system is superb. Similarly-superb is the 5-stop dynamic image stabilization system, adding greatly to the versatility of this rather-narrow max aperture lens. The RF 24-240 is nicely designed and seems well built with the overall package being comfortable in size and weight.

With understanding and acceptance of its shortcomings, primarily related to corner image quality, the RF 24-240 can easily replace two other lenses in a kit and avoids lens changes, a task that we otherwise might not bother doing (laziness or ... I'd rather call it "efficiency") or perhaps might not have time to do (fleeting opportunities). This easy-to-take-with-you lens is especially well-suited for travel, family events, etc. and it does not cost a fortune. Avoiding the corners due to aspect ratio, not needing wide apertures for adequate light levels, video recording, aided by the dynamic image stabilization feature, is a great use for this lens.

While the fun-to-use Canon RF 24-240mm F4-6.3 IS USM Lens will likely find more homes with amateur photographers, there are reasons for even a seasoned professional to have this lens model. I've personally found this a convenient lens to have available.

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My Recommended Canon RF 24-240mm F4-6.3 IS USM Lens Retailers

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