Canon RF 100-500mm F4.5-7.1 L IS USM Lens Review

It was only a matter of time. A telephoto zoom lens with long focal lengths is a staple in many kits, and Canon's first such lens in the RF mount was anxiously awaited. The RF lens series is being filled with ultra-high performing models, and the Canon RF 100-500mm F4.5-7.1 L IS USM Lens, getting the professional-grade L-series designation, is another stellar performer, a must-have lens for many kits, including mine.

When introducing the Canon EOS R with the RF mount, Canon's first full-frame lens mount introduced since the EF (electronic focusing) mount was introduced over 30 years prior, Canon's engineers promised that all RF lenses would have advantages over their EF counterparts. Those advantages would include smaller size, lighter weight, and/or new features.

In this case, indisputable is that we gain a welcomed 100mm of focal length on the long end, and lost is about 14% of the weight. While the size of this lens is slightly increased, the smaller size of the R-series cameras offsets the difference, and the overall weight difference is substantially less.

Canon's engineers indicated that image quality, advantaged by new lens design opportunities made available by the optimized RF mount, would be minimally equivalent and often better. Canon's earliest RF mount lenses set the image quality bar high, and this lens is exciting in that regard.

The Canon RF 100-500mm F4.5-7.1 L IS USM Lens features a long focal length range, ideal for wildlife and sports photography and perfect for families capturing memories while chasing their kids. With features like a Dual Nano USM AF system, close minimum focusing distance, 5-stop image stabilization, weather sealing, and ready for the rigors of professional use build quality, this lens is impressive in all regards.

You will need a camera with an RF-mount (the EOS R-series) to use this lens. Still, the RF 100-500 is good enough to justify buying an RF-mount camera just to enable its use, and the latest R-series cameras need little additional justification.

Focal Length Range

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Choosing the right focal length or focal length range is of utmost importance for lens selection. The focal length determines the perspective and framing combination. With a range that starts at 100mm (short telephoto) and goes to a super-telephoto 500mm (before adding extenders/teleconverters), this lens covers a wide range of uses, including many general-purpose telephoto needs. In the past, I have had a 100-400mm lens with me a significant percentage of the time when out shooting. The RF 100-500 takes that lens's place in my kit, providing an additional, significant 100mm on the long end.

One of the best uses for the 100-500mm focal length range is wildlife photography. At the wide end of the range, large or close wildlife can be contained in the frame, and environmental portraits can often be created. From the other perspective, when the wildlife is scared of you (or vice versa) or you cannot or do not want to approach more closely, 500mm permits capturing images of distant subjects rendered large in the frame. Smaller birds and animals, chipmunks for example, often need longer focal lengths to have a substantial size in the frame even at close distances, and these subjects are included on this telephoto zoom lens's uses list.

Staying with the fauna theme, the RF 100-500 is an ideal zoo and safari lens option.

A 100-500mm lens is often a great choice for photographing people. The wide end has great portrait photography capabilities, even indoors, if adequate ambient light is available. The mid and long focal lengths, typically most-easily used outdoors, will provide a more-compressed appearance (due to the longer subject distance), and these focal lengths bring the potential for a strong background blur (long focal lengths magnify the background blur). Parents chasing kids can also find plenty of uses for this entire focal length range, including for their at-the-park and at-the-beach needs. This focal length range is ideal for headshot portraits.

People participating in sports make great subjects for this lens. While selecting a telephoto lens is a good choice from a safety perspective (safety both from and for the subject), it is also a good choice when there is a physical or designated barrier to getting closer, such as a fence or the perimeter lines on a sports field. Sometimes, the action can be close, and sports photography needs can range all of the focal lengths this lens avails. A full-frame camera-mounted 500mm lens will reach deep into large field events, covering a significant portion of even large soccer, football, field hockey, lacrosse, etc. fields. At the same time, even close action will be nicely handled by the wide end of this zoom lens. A zoom range (vs. using a prime or single focal length lens) means that the proper cropping of a subject can be established and maintained over a wide range of subject distances, resulting in full use of your camera's imaging sensor, creating optimal image quality.

I use all of the focal lengths in this lens for landscape photography. I often find it easy to create attractive, compressed-perspective landscape images when using a telephoto lens. Note that long focal lengths can make even a mediocre sunrise or sunset look amazing. This lens is a great choice for smaller flora, such as the flowers in your garden.

Wildlife, sports, and landscape photographers make up a large percentage of the owners of this lens, but there are plenty of other uses for this wide 5x focal length range. Photojournalists, especially those with restricted access to their subjects, may find this focal length range useful. With the close minimum focus distance, this lens will work excellently for product photography. This lens is exceptionally well represented at air shows.

Sometimes, laziness (perhaps "relaxation" sounds better) is a good reason to use the 100-500mm focal length range. Sit in the comfort of your car, avoid the need to cross a creek, stay back from the surf, etc. A benefit of having the wider focal lengths available is that photos can be framed appropriately from in front of line-of-sight obstacles.

I've only touched on a small percentage of the uses for this lens. If I am not using it as my primary lens, the RF 100-500mm lens will be handling much of the balance of my needs, including complementing a 600mm lens when photographing wildlife or a 24-70mm lens when photographing landscapes.

Here are examples of what this huge focal length range looks like:

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When used on an ASP-C firmat camera model, the 1.6x FOVCF sensor format will see an angle of view similar to a full-frame-mounted 160-800mm lens. This shifted-narrower angle of view range takes this lens's uses deeper into the sports and wildlife pursuits, with bird photography and big-field sports being especially good choices for this focal length range. While this range is still be useful for portrait photography on an APS-C camera, tightly-framed portraits would be most comfortable with considerable space needed for full body portraiture.

Max Aperture

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As always, the lower the aperture number, the more light the lens will allow to reach the sensor. Each "stop" in aperture opening reduction (examples: f/2.8, f/4.0, f/5.6, f/8, f/11) reduces the amount of light reaching the sensor by a factor of 2, a substantial amount. Allowing more light to reach the sensor permits freezing action and handholding the camera in lower light levels and can also permit the use of lower, less noisy, ISO settings. In addition to allowing more light to reach the sensor, increasing the aperture opening permits a shallower DOF (Depth of Field) that creates a stronger, better subject-isolating background blur (at equivalent focal lengths).

Because the aperture is measured as a ratio of lens opening to focal length and because this lens's maximum opening does not increase adequately with focal length increase to maintain the same ratio, this lens's max aperture is a variable one, ranging from f/4.5 to f/7.1 as the focal length is increased. These are relatively narrow apertures at any specific focal length.

The advantages of a narrow aperture are primarily related to the lens elements being significantly smaller in size. The benefits include a smaller overall lens size, a lighter weight, and a lower cost. Those are factors that we all can appreciate, and they apply to this specific lens.

The variable max aperture design provides the same size, weight, and cost efficiencies while delivering the widest aperture possible at each focal length. A downside is that the widest available max aperture, f/4.5, cannot be used over the entire focal length range. Your camera will automatically account for the change in auto exposure modes, but making use of the widest-available aperture in manual exposure mode is complicated somewhat.

For many, especially those already owning the impressive Canon EF 100-400mm f/4.5-5.6L IS II USM Lens (or any other Canon telephoto zoom lens), the unusually narrow to-f/7.1 spec on the Canon RF 100-500mm F4.5-7.1 L IS USM Lens gives us pause. In part, the Dual Pixel CMOS AF system in Canon's R-series cameras autofocus lenses with narrow apertures adequately, making narrow openings quite usable. None of us was disappointed by the to-500mm part of the spec, but we still wanted to know if the aperture opening size was being sacrificed at the 400mm aperture in order to keep this lens compact and light.

What is the Canon RF 100-500mm F4.5-7.1 L IS USM Lens's maximum aperture opening at 400mm?

Answer 1: When the camera is set to 1/3-stop increments, the maximum 400mm aperture reported to the camera is rounded to f/6.3.

Answer 2: When the camera is set to 1/2-stop increments, the maximum 400mm aperture reported to the camera is rounded to f/5.6.

I know, you are now planning to change your R-series cameras to use 1/2-stop increments. Don't bother as the difference is how the actual opening size is rounded (the true aperture is likely between these two numbers), likely holds for only a short range of focal lengths, and even if there was a 1/3-stop difference, the difference in noise made visible by an offsetting 1/3-stop ISO change will not matter to most. If the RF 100-500mm lens is an estimated f/6.0 at 400mm, the difference between it and the EF 100-400's f/5.6 is especially slight. Adobe software says that 400mm is f/6.2 and 500mm is 7.0.

Again, do not overlook the fact that 500mm is a substantially longer focal length than 400mm. Both lenses are compatible with extenders, and with the 1.4x mounted, the EF 100-400 L II's focal length range reaches to 560mm, but with a resulting max aperture of f/8.

Here is a comparative look at the max aperture step-down by focal length for this class of lens with an additional column necessitated by this lens.

Model	f/4.5	f/5.0	f/5.6	f/6.3	f/7.1
Canon EF 100-400mm f/4.5-5.6L IS II USM Lens	100-134mm	135-311mm	312-400mm
Canon RF 100-500mm F4.5-7.1 L IS USM Lens	100-150mm	151-253mm	254-362mm	363-471mm	472-500mm
Nikon 80-400mm f/4.5-5.6G AF-S VR Lens	80-134mm	135-249mm	250-400mm
Sigma 100-400mm f/5-6.3 DG OS HSM C Lens		100-111mm	112-233mm	234-400mm
Sigma 150-600mm f/5-6.3 DG OS HSM Sports		150-184mm	185-320mm	321-600mm
Sigma 150-600mm f/5-6.3 DG OS HSM C Lens		150-179mm	180-387mm	388-600mm
Sony FE 100-400mm f/4.5-5.6 GM OSS Lens	100-115mm	116-161mm	162-400mm
Tamron 150-600mm f/5-6.3 Di VC USD G2 Lens		150-212mm	213-427mm	428-600mm

While the RF 100-500 holds f/4.5 modestly deeper into the focal length range, the EF 100-400 L II holds a modest advantage at the longer focal lengths. Still, the differences are minor, and the RF 100-500 has a relatively wide aperture in its class.

Overall, this lens is not the ideal choice for stopping low light action. When the sun goes down, action sports photographers using this lens (or similar models) will be reaching for high (noisy) ISO settings to keep images bright enough when using the fast shutter speeds needed to freeze their subjects' motion. This lens is not the best choice for indoor sports or for photographing anything else that moves in low light.

Need f/54? This lens has you covered.

With the relatively narrow apertures, this lens cannot create the shallowest depth of field among comparable focal length lens, but by virtue of its long focal lengths, it will create a strong background blur.

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At 500mm, the background is a detail-less color blur.

Image Stabilization

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This lens begs to be used handheld, and perhaps no lenses are better versatility-improved by image stabilization than narrow aperture telephoto lenses. The Canon RF 100-500mm F4.5-7.1 L Lens's refined 5-stop IS system greatly increases its usability and provides considerably improved image quality. When used on Canon R-series cameras featuring IBIS (In-Body Image Stabilization), including the EOS R5 and EOS R6, coordinated image stabilization control takes this IS system's rating up to an even more impressive 6 stops.

Put a camera with this lens mounted to your eye with IS turned off, and a jittery image is what you should expect to see. Move the IS switch to the on position, and the difference is dramatic, with the scene becoming motionless.

While IS is great for reducing camera shake-caused blur in images, it is also helpful for precise framing of subjects in the viewfinder.

Aiding AF precision is another image stabilization benefit that should not be overlooked. The camera's AF system can produce better focus precision if the image it sees is stabilized. Canon contends that this is true even with a subject that is in motion and at action-stopping shutter speeds.

It was not my steadiest day, but this lens set to 100mm (on the EOS R5) still turned out a high percentage of sharp images at 1/4-second exposures, with most 0.3-second images being rendered sharply. At 500mm, a high percentage of 1/40-second exposures were sharp, and most 1/30-second exposures were sharp. Again, I wasn't my steadiest on this day yet the camera and lens combination still turned in good results.

Only a faint whirring can be heard from this IS system by an ear next to the lens in a quiet environment. The IS sound is always present, even when IS is switched off. Drifting of the scene is minor except when coming to a stop after panning, or when used on a tripod. Handheld video recording is greatly aided by this IS system.

As with many of Canon's L-series telephoto lenses, three IS modes are provided on the RF 100-500 — Mode 1 (general-purpose), Mode 2 IS (for panning with a subject with 1 axis of stabilization provided), and Mode 3. Mode 3 is useful for tracking erratic action. In Mode 3, image stabilization is active and ready for use the moment the shutter releases. However, actual stabilization is not in effect until that precise time, then acting as Mode 2 IS with panning motion detection in effect, providing Image Stabilization at right angles to the direction of the movement. The view seen through the viewfinder is not stabilized, allowing an erratic subject to be tracked without fighting against the image stabilization system trying to stabilize the view. Mode 3 (and off) permit easy, precise framing when the lens is mounted on a tripod.

This image stabilization system is tripod-compatible, but Canon suggests that IS might not be fully effective when using a tripod. Depending on the scenario (stability of the mount, shutter speed, etc.), switching IS off may be best.

Especially at 500mm, it is possible to move the lens outside of the image stabilization capabilities. The image stabilization system is a huge aid to sharp handheld images, though it does not work miracles. Whether you need to leave the tripod behind or just want the speed and freedom afforded by handholding, the RF 100-500mm lens's image stabilization is there for you.

Image Quality

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Is the Canon RF 100-500mm F4.5-7.1 L IS USM Lens sharp? My expectation was that we were going to be happy with the performance of this lens, performance at least as good as the phenomenal Canon EF 100-400mm f/4.5-5.6L IS II USM Lens that preceded it. My expectation was strong enough that I preordered this lens, and my years of experience using this lens indicates that was a good move. My EF 100-400 L II was sold quickly after testing the new lens.

Succintly stated, the Canon RF 100-500mm F4.5-7.1 L IS USM Lens creates extremely sharp images from full-frame corner to full-frame corner, including at wide-open apertures, over the entire focal length range. This lens turns in outstanding performance.

Next, I'll share some less-formally-captured (not laser-aligned, not lit by flash, precise focus distance per focal length not adhered to) test results. I usually take this testing outdoors, but with dark clouds and rain predominating, I was impatient and set up a large test chart indoors. The images below are 100% resolution center of the frame crops from images captured in RAW format using a Canon EOS R5. The images were processed in Canon's Digital Photo Professional using the Standard Picture Style with sharpness set to "1" (0-10 scale) and brightened by 0.5-stops. Note that images from most cameras require some level of sharpening but too-high sharpness settings are destructive to image details and hide the deficiencies of a lens.

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Except for slight camera movement showing between some images, it is hard to know if the proper test images are loading. I'm jumping ahead in regards to the extender discussion, but I wanted you to see how impressive this lens performs with the RF extenders. Yes, there is an impact with the 2x, but these results readily improve with increased sharpness, the "S" designation.

In some lens designs, the plane of sharp focus can move forward or backward as a narrower aperture is selected. This effect 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 (1000mm results are extreme-top-right) captured and processed identically to the above center-of-the-frame images. The lens was focused in the center of the frame to capture these images, meaning any curvature of the plane of sharp focus would be revealed.

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Samples taken from the outer extreme of the image circle, full-frame corners in this case, can be counted on to show the worst performance a lens is capable of. However, these results are really nice.

Corner sharpness does not always matter, but for some disciplines, including landscape photography and environmental wildlife portraiture, two uses this lens is ideally suited for, it matters a lot. This lens has the sharp corners requirement covered.

When used on a camera that utilizes a lens's entire image circle, peripheral shading can be expected at the widest aperture settings. Fortunately, the amount of shading produced by this lens is low, 1.5 stops or less at worst, and about 0.3 stops at f/11.

APS-C format cameras using lenses projecting a full-frame-sized image circle avoid most vignetting problems. In this case, the under 1 stop of wide-open shading will seldom be visible.

One-stop of shading is the amount often used as the visibility number, though subject details provide a widely varying amount of vignetting discernibility. Vignetting is correctable 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. Study the pattern showing in our vignetting test tool to determine how your images will be affected.

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 most significant amount as this is where the most significant difference in the magnification of wavelengths typically exists.

With the right lens profile and software, lateral CA is often easily correctable (often in the camera) by radially shifting the colors to coincide. However, it is always better not to have the problem in the first place. 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. These are 100% crops from the extreme top left corner of ultra-high-resolution EOS R5 frames showing diagonal black and white lines.

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There should only be black and white colors in these images, with the additional colors showing the presence of lateral CA. For a zoom lens, the amount of color separation shown here is quite mild. There is modest lateral CA at 100mm, but most of the balance of the focal length range is practically free from this effect. The color fringing reverses, becoming mild again at 500mm.

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 observe. Axial CA remains at least somewhat persistent when stopping down with the color misalignment effect increasing with defocusing. 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. Any fringing color differences in the highlights created from the neutrally-colored subjects were introduced by the lens.

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While I see some mild fringing color differences at the wide end, this lens performs well overall in this regard.

Flare and ghosting are caused by bright light reflecting off the surfaces of lens elements, resulting in reduced contrast and sometimes-interesting artifacts. Combating these issues is Canon's Air Sphere Coating (ASC), but with 20 elements in 14 groups (the EF II has 21/16) and long focal lengths, some flaring can still be expected. Our standard flare testing uses the sun in the corner of the frame, and most telephoto zoom lenses show noticeable flaring in this test, especially at narrow apertures. Surprisingly, this lens, though not flare-free, shows relatively few flare effects. Things go wonky at 500mm, but having the sun in the frame at 500mm is not a good idea in the first place.

Flare effects can be embraced or avoided, or removal can be attempted. Removal is sometimes challenging.

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). Coma clears as the aperture is narrowed. Astigmatism is seen as points of light spreading into a line, either sagittal (radiating from the center of the image) or meridional (tangential, perpendicular to sagittal). Remember that lateral CA is another aberration apparent in the corners.

The images below are 100% crops taken from the top-left corner of EOS R5 frames.

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Photographing stars with a telephoto lens and no tracking mount is challenging, but these results are quite good.

Rare is a zoom lens completely free from geometric distortion over its entire focal length range. At 100mm, this lens has negligible distortion. As the focal length is increased, pincushion distortion appears, getting stronger until about 400mm. The distortion amounts, at worst, are not bad.

Most modern lenses have lens correction profiles available, and distortion can easily be removed using these. geometric distortion correction requires stretching which is detrimental to image quality.

As seen earlier in the review, the amount of blur a lens can produce is easy to show, and telephoto lenses are advantaged in this regard. Assessing the quality is more challenging due in part to the infinite number of variables present in all available scenes. Here are some f/11 (for aperture blade interaction) examples.

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The first set of 100% crop examples show defocused highlights being rendered in nice quality. The circles are nicely rounded and evenly filled. The full reduced images in the second set of examples also look great.

Except for a small number of specialty lenses, the wide aperture bokeh in the corner of the frame does not produce round defocused highlights with these effects taking on a cat's eye shape due to a form of mechanical vignetting. If you look through a tube at an angle, similar to the light reaching the corner of the frame, the shape is not round. That is the shape seen here.

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As the aperture narrows, the entrance pupil size is reduced, and the mechanical vignetting absolves with the shapes becoming rounder.

When the aperture is stopped down, point light sources will show a sunstar effect of some form. Each blade is responsible, via diffraction, for creating two points of the star effect. If the blades are arranged opposite of each other (an even blade count), the points on the stars will equal the blade count as two blades share in creating a single pair of points. The blades of an odd blade count aperture are not opposing and the result is that each blade creates its own two points. This lens's nine-blade count times two points means 18-point star effects.

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The examples above were captured at f/16. In general, the more a lens is stopped down, the larger and better shaped the sunstars tend to be, and we see that in these examples — the more-stopped-down 100mm results have nice star shapes, while the less-stopped-down 500mm stars are not as dramatic. A narrow aperture lens does not afford much stopping down prior to reaching apertures where diffraction causes noticeable softening of an image and typically does not produce the biggest or best-shaped sunstars.

"The RF100-500mm F4.5-7.1 L IS USM lens features an optical design built specifically for the RF mount. This includes one Super UD lens, plus six UD elements to reduce both axial chromatic aberration and chromatic aberration of magnification to achieve high image quality throughout the zoom range." [Canon]

Overall, the Canon RF 100-500mm F4.5-7.1 L IS USM Lens produces outstanding image quality.

Focusing

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Unless in manual focus mode, a lens's autofocus performance is an extremely important factor in realizing the image quality capability of a lens. To that point, the Canon RF 100-500mm F4.5-7.1 L IS USM Lens, like the Canon RF 70-200mm F2.8 L IS USM Lens, gets an advanced, high-performing AF system driven by Dual Nano USM (Ultrasonic) focus motors.

While Canon has been designing Nano USM AF systems into the latest L-series RF lenses, this dual-motor design is being featured for only the second time in the RF 100-500. What Canon said about the RF 70-200 Dual Nano AF system again applies: "The lens also incorporates a floating focus control ... that drives the two lens groups individually while using the two aforementioned Nano USM motors. The floating focus lens element shortens focusing distance, providing users with fast, consistent and reliable performance."

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 and smoothly. Cameras featuring Dual Pixel CMOS AF and Movie Servo AF make video recording easy, and Nano USM lenses are well-suited for this task. The smooth focusing makes focus distance transitions easy on the viewer's eyes, and the sound of the lens focusing should not be picked up by the camera's mic. This lens's aperture changes are silent and smooth.

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." The RF 70-200 Dual Nano USM system is pictured above.

Ring USM was Canon's former preference for high-end lens AF systems. While most Ring USM lenses are great performers, they generally do not focus so smoothly in Movie Servo AF, and Ring USM EF lenses produce considerably more focus chatter. Nano USM lenses autofocus substantially smoother and quieter than Ring USM lenses.

Of utmost importance is AF accuracy, and from that perspective, all of the Nano USM-driven AF systems to date, including this one, have performed impressively.

The RF 100-500 provides a focus limiter switch, permitting the autofocus range to be limited to 9.8' (3m) - ∞. If subjects are known to be within the narrower range, focus lock times may be decreased by using this switch.

Like the RF 70-200mm f/2.8 and the EF 100-400 L II, the RF 100-500's mid-sized, ribbed-rubber-coated manual focus ring is positioned behind the zoom ring. I often complain about rear-positioned focus rings being near the lens balance point, making them too easy to inadvertently turn with the left hand while operating the zoom ring and while changing composition (including leveling the camera). I'm still not fond of this design choice, but this focus ring is back far enough that, especially when the lens foot is in hand, I'm not inadvertently turning it. That said, all lenses in this class share this trait. Position your left hand slightly forward of the manual focus ring or disable electronic manual focusing after One-Shot AF in the camera's menu to avoid any such problems.

Like STM, Nano USM utilizes a focus-by-wire or electrical manual focus design (vs. a direct gear-driven system) with the manual focus ring electronically controlling 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. Note that FTM requires electronic manual focusing after One-Shot AF to be enabled in the camera's AF menu. The lens's 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 prefer a linear adjustment speed, and have my cameras configured for such. That said, a least on the EOS R5, a variable manual focus rate is not available. The RF 100-500mm L Lens manual focus is adjusted at a nice rate, with approximately 120° of ring rotation from MFD to infinity.

The manual focus ring has light resistance, and adjustments are smooth and solidly centered with no unusual framing shift occurring. Precise manual focusing capabilities are provided.

Normal is for the composition to change size in the frame (sometimes significantly) as focus is pulled from one extent to the other. This is referred to as focus breathing, a change in focal length resulting from a change in focus distance. Focus breathing negatively impacts photographers intending to use focus stacking techniques, videographers pulling focus, and anyone critically framing while adjusting focus. This lens shows a moderate amount of focus breathing.

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While it can be an individual lens-specific attribute, the review lens does not exhibit parfocal-like behavior. Though it attempts to adjust the focus distance to be appropriate for the selected focal length, focusing at the long end and zooming to the wide end does not result in precise focus. If you adjust the focal length, re-establish focus as suggested by these 100% crops focused at 500mm.

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The 500mm result, sharpened in DPP to only "1", is another look at the sharpness being delivered by the R5 and RF 100-500mm combo. Yes, the Canon EOS R5 eye AF can detect the eyes of human-made animals, including frog pool floats.

A focus distance window is not provided, but a focus distance meter shows in the lower portion of the camera's electronic viewfinder during manual focusing.

With a minimum focus distance of 35.4" (900mm), shorter than that of the already great EF 100-400 L II capability, this lens has a attractive 0.33x maximum magnification spec at 500mm.

Model	Min Focus Distance "(mm)		Max Magnification
Canon EF 100-400mm f/4.5-5.6L IS II USM Lens	38.4	(980)	0.31x
Canon RF 100-400mm F5.6-8 IS USM Lens	34.6	(880)	0.41x
Canon RF 100-500mm F4.5-7.1 L IS USM Lens	35.4	(900)	0.33x
Canon RF 200-800mm F6.3-9 IS USM Lens	31.5	(800)	0.25x
Nikon 80-400mm f/4.5-5.6G AF-S VR Lens	68.9	(1750)	0.20x
Sigma 100-400mm f/5-6.3 DG OS HSM C Lens	63.0	(1600)	0.26x
Sigma 150-600mm f/5-6.3 DG OS Sports Lens	102.4	(2600)	0.20x
Sigma 150-600mm f/5-6.3 DG OS C Lens	110.2	(2800)	0.20x
Sony FE 100-400mm f/4.5-5.6 GM OSS Lens	38.6	(980)	0.35x
Sony FE 200-600mm f/5.6-6.3 G OSS Lens	94.5	(2400)	0.20x
Tamron 150-600mm f/5-6.3 Di VC G2 Lens	86.6	(2200)	0.26x

As often the case, this lens focuses closer at the widest focal length. Here are some specific examples:
 
At 100mm: 2.95' (0.9m) — 0.12x maximum magnification
At 300mm: 3.28' (1.0m)
At 500mm: 3.94' (1.2m) — 0.33x maximum magnification

At 100mm, a subject measuring approximately 9.5 x 6.3" (241 x 161mm) fills the frame of a full-frame camera at the minimum focus distance. At 500mm, a subject measuring approximately 4.2 x 2.8" (117 x 78mm) does the same.

This lens is a great choice for photographing butterflies and flowers.

Need a shorter minimum focus distance and higher magnification? An extension tube mounted behind this lens should provide a modest decrease and increase, respectively. Extension tubes are hollow lens barrels that shift a lens farther from the camera, allowing 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 offer RF mount-compatible extension tubes, but third-party options are available.

Extenders / Teleconverters

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An even better option for increasing the magnification of this lens is to use extenders, also referred to as teleconverters. The Canon RF 100-500mm F4.5-7.1 L IS USM Lens is compatible with the simultaneously announced Canon RF 1.4x Extender and Canon RF 2x Extender — with a catch.

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These extenders, like most other high-performing options, have a front extension that requires room behind the mounted lens's rear element. With some EF lenses, we found that Canon EF extenders were compatible with lenses Canon did not indicate being compatible (such as the Canon EF 70-300mm f/4-5.6L IS USM Lens) under a condition. If the lens was zoomed to a specific minimum focal length, the rear element moved forward enough to clear the extender. That is the case with the RF 100-500, and 300mm is that minimum compatible focal length.

The RF 100-500 physically prevents an extender from being mounted behind it at focal lengths below 300mm, and physically prevents the lens from being zoomed to focal lengths wider than 300mm when an extender is attached. After detaching an extender, the lens may need to be zoomed to a focal length longer than 300mm prior to zooming out to wider angles, especially if any pressure was being applied to the front, such as occurs when sitting upright on a desk. This feature prevents the lens from collapsing when the extender is removed.

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Mounting the Canon RF 1.4x Extender behind the RF 100-500 creates a 420-700mm f/8-10 image stabilized lens. Those focal lengths will be attractive to wildlife and sports photographers, but the max aperture range will not be as welcomed.

There is always some image quality reduction with an extender mounted, but the 1.4x caused degradation is quite minor, as it is with the EF 100-400 L II. Lateral CA is increased slightly, impacting corner sharpness modestly. AF speed is mildly impacted with this extender in use, with performance remaining excellent in even rainy outdoor conditions.

Mounting the Canon RF 2x Extender behind the RF 100-500 creates a 600-1000mm f/11-14 image stabilized lens (that goes to f/91). Those focal lengths will be especially attractive to bird photographers, and the max aperture range will again not be as welcomed, sending ISO settings noisy-high in many circumstances.

The image degradation caused by the addition of a 2x extender into a lens's optical design is usually strong, with contrast and resolution taking hits. That said, as seen earlier in the review, this lens performs reasonably well with the 2x mounted, exceeding my expectations. Especially with a bit of extra sharpening applied, 1000mm results from this lens are quite usable. Lateral CA is increased a noticeable amount by the RF 2x.

Extenders always impact AF speed, but performance remains good in even rainy outdoor conditions. Expect some focus hunting in low light scenarios. Simply being able to autofocus an f/14 max aperture lens is a superpower of some of Canon's latest R-series cameras, including the R5 and R6.

Note that this lens cannot fully retract for storage while an extender is mounted.

Build Quality & Features

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The Canon RF 100-500mm F4.5-7.1 L IS USM Lens has construction similar to the other recently introduced white Canon L-Series lenses, with membership indicated by the red ring and the "L" in the moniker. Members of this best-available series of professional-grade lens models are built tough, ready for the rigors of daily professional use. Those familiar with Canon's RF 70-200mm F2.8 L lens and similar EF models will not be disappointed with this one.

While Canon's RF L lenses take on a slightly updated look from the EF counterparts, those familiar with EF L lenses will immediately recognize this lens's heritage. Expect the RF 100-500 lens to have excellent fit and finish, similar to the RF 70-200 f/2.8.

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The Canon RF 100-500mm F4.5-7.1 L IS USM Lens has an aesthetically pleasing design featuring a smooth, rather wide exterior diameter that is comfortable in hand. Much of the lens exterior is constructed of high-quality engineering plastic.

The forward-positioned rubber-coated zoom ring is substantial in size, measuring 2.47" (62.8mm). It is smooth in rotation and has no play, and the 120° amount of rotation is ideal for easy adjustment. Full extent zooming feels most natural with a finger reset on the zoom ring midway through the rotation.

All Canon RF lenses feature a knurled Control Ring, able to be configured for fast access to settings including aperture, ISO, and exposure compensation. Positioning this ring behind the tripod ring makes it easy to find while keeping it out of the way of the other two rings. Note that the control ring is clicked by default, and this ring's clicks are going to be audible in camera-based audio recordings. Canon offers a control ring click stop removal service (at a cost).

The RF 100-500 L lens gets the heat shield coating, including the white color, of the RF 70-200. While a white lens might be less stealthy, garnering more attention than a black lens, white remains significantly cooler under a bright sun, reducing the temperature change and any negative issues that such contributes to, including part expansion, for consistent operation in high temperatures. I'll let you decide if white appears more professional, but white does hide dirt and dust better than black.

The RF 100-500 gets a full complement of switches. All of the switches are shallow, with the IS-related switches being tactilely delineated by a slightly raised area of the lens. Based on the RF 70-200 design, these switches have sufficient raised area in the center to make them easily usable, even with gloves on. Note that the RF 100-400's switches are in front of the tripod ring vs. near the mount on the EF 100-400 L II, making room for the control ring.

Like most lenses in its class, the RF 100-500 features an extending design, and like the EF 100-400 L IS II, the RF 100-500 utilizes a rotational type zoom ring (vs. a push-pull design). Prefer push and pull? Grasp the front of the lens at the base of the hood and do that. The 500mm end becomes a bit tight, but the method works well at most focal lengths.

Also like the EF 100-400 L IS II, the RF 100-500 features a torque adjustment ring, dubbed the Zoom Touch Adjustment Ring (ZTAR) in the predecessor. Positioned between the zoom ring and switch panel, the torque adjustment ring allows the zoom friction to be set as desired, though not completely locked. While many lenses provide a zoom lock switch that is usable only with the lens in its most-retracted position, the torque adjustment ring offers far more flexibility. Rotate the ring a short amount to adjust the focus ring resistance between smooth and tight, the latter permitting any focal length settings to be firmly held, greatly enhancing a strong upward or downward angle shooting experience. Slightly unusual is that my ring has a bit of flex to it when in the tight position.

This lens is weather-sealed and built for outdoor professional use in conditions that are not always favorable. Sometimes unfavorable conditions happen indoors, including on my desk. Immediately upon arrival, I captured product images of the RF 100-500 and then set it on the desk beside me, balanced on the lens foot with an EOS R5 mounted. Not long after doing so, I bumped the camera with my elbow. The lens tipped on its side, knocking over a large cup of water, which dumped onto the top of the lens. While I don't regularly test expensive weather-sealed lenses by pouring water on them, this was a perfect test. I didn't panic because I knew the lens was built to easily withstand such incidents, and no harm was done.

Lenses that extend move air in and out during use. To avoid dust and moisture entry, this lens design includes a ventilation route that permits airflow while filtering dust and moisture.

The front and rear elements are fluorine-coated, helping dust and water drops to shed off (or easily blow off) of the front and rear lens elements. Cleaning more problematic issues, such as fingerprints, is much easier to accomplish with this coating, and the difference is especially appreciated in the field.

The RF 100-500 gains 100mm of focal length range over the EF 100-400 L II while losing 14% of its weight. Disappointed about that feature is no one. Weighing in at 48.1 oz (1,365g), the RF 100-500 is not a light lens. However, this lens is light for its class.

Model	Weight oz(g)		Dimensions w/o Hood "(mm)		Filter	Year
Canon EF 100-400mm f/4.5-5.6L IS II USM	55.4	(1570)	3.7 x 7.6	(94.0 x 193.0)	77mm	2014
Canon RF 100-400mm F5.6-8 IS USM	22.4	(635)	3.1 x 6.5	(79.5 x 164.7)	67mm	2021
Canon RF 100-500mm F4.5-7.1 L IS USM	48.1	(1365)	3.7 x 7.6	(93.8 x 207.6)	77mm	2020
Canon RF 200-800mm F6.3-9 IS USM	72.4	(2050)	4.0 x 12.4	(102.3 x 314.1)	95mm	2023
Nikon 80-400mm f/4.5-5.6G AF-S VR	55.4	(1570)	3.8 x 8.0	(95.5 x 203.0)	77mm	2013
Sigma 100-400mm f/5-6.3 DG OS HSM C	40.9	(1160)	3.4 x 7.2	(86.4 x 182.3)	67mm	2017
Sigma 150-600mm f/5-6.3 DG OS HSM C	68.1	(1930)	4.1 x 10.2	(105.0 x 260.1)	95mm	2015
Sigma 150-600mm f/5-6.3 DG OS Sports	101.0	(2860)	4.8 x 11.4	(121.9 x 289.6)	105mm	2014
Sony FE 100-400mm f/4.5-5.6 GM OSS	49.2	(1395)	3.7 x 8.1	(93.9 x 205.0)	77mm	2017
Sony FE 200-600mm f/5.6-6.3 G OSS	74.8	(2120)	4.5 x 12.5	(115.5 x 318.0)	95mm	2019
Tamron 150-600mm f/5-6.3 Di VC G2	71.0	(2010)	4.3 x 10.2	(108.4 x 260.2)	95mm	2016
Tamron 150-600mm f/5-6.3 Di VC	68.8	(1950)	4.2 x 10.1	(105.6 x 257.8)	95mm	2013

For many more comparisons, review the complete Canon RF 100-500mm F4.5-7.1 L IS USM Lens Specifications using the site's lens specifications tool.

Here is a visual comparison:

Positioned above from left to right are the following lenses:

Canon EF 100-400mm f/4.5-5.6L IS II USM Lens
Canon RF 100-500mm F4.5-7.1 L IS USM Lens
Sigma 150-600mm f/5-6.3 DG OS HSM C Lens
Sony FE 200-600mm f/5.6-6.3 G OSS Lens

The same lenses are shown below with their hoods in place.

Use the site's product image comparison tool and big lens product image comparison tool to visually compare the Canon RF 100-500mm F4.5-7.1 L IS USM Lens to other lenses. Note that the above visual comparisons are especially relevant for those comparing between camera systems. Those committed to the R-series need to also account for the mount adapter size.

Tripod rings provide balanced tripod mounting of a camera and lens, avoiding tripod head and camera strain, avoiding sag after lock-down, and allowing easy camera rotation. Canon includes the Tripod Mount Ring F (WIII) with this lens.

Like the RF 70-200 Mount Ring E design, the RF 100-500's lightweight tripod mount ring is somewhat tall, leaving adequate room for fingers over the foot, yet compact. This is a solid mount with slight flex at the ring, and when the locking knob is tightened with relatively light pressure, the ring locks tightly. The RF 100-500's Mount Ring is not riding on steel bearings, and the friction fit is not especially smooth during rotation until the locking knob is quite loose. I initially didn't like the RF 70-200 ring's smoothness but have acclimated to using a less-tight knob setting than seems right to obtain smooth rotation (I have a tendency to over-tighten anything that screws down).

It is often beneficial to have a tripod ring locked in a precise 90° angle increment. While this ring does not have click stops to indicate these positions, the collar has indicator lines that can be aligned with a tiny notch on the top of the lens barrel.

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As indicated by the low-profile hinge on the top, the RF 100-500's tripod mount ring is removable. Fully loosen the lock knob, and then pull it out to release the tripod collar completely, unhinging it while the lens is still mounted to the camera. Unlike the EF 100-400 L II's foot, the RF 100-500 L's foot is not removable, and replacement lens feet will require the entire ring to be replaced. Consider a Wimberley P20 Lens Plate for use in Arca-standard quick-release clamps.

Weight specifications omit the tripod mount ring when such is removable, an attractive reason for manufacturers to make the ring removable in the first place (and a reason to sometimes remove the ring). The Tripod Mount Ring F (WIII) adds approximately 5.6 oz (160g) to the in-use weight.

The RF 100-500 lens uses ultra-common standard 77mm threaded filters. Filters of this size are somewhat large, but a huge number of lenses using 77mm filters makes effects filter options such as circular polarizer and neutral density filters easy to share. Larger filters cost more than small ones, but sharing is cost-reducing, and fewer filters consume less space in the backpack.

Standard is for the lens hood to be included in the box with Canon L-series lenses. The RF 100-500 comes with the white color matching ET-83F (WIII) lens hood, the same hood included with the RF 70-200, in the box. The slightly flexible (helpful for absorbing impact), molded plastic ET-83F hood has a matte finish with a mold-ribbed interior and a stylish black finish on the front (this is not a rubberized surface). The round shape nicely facilitates use as a camera stand when conditions permit. The ET-83F (WIII) is a relatively large hood that adds significant protection to the front lens element – protection from bright flare-causing lights, protection from scratch-causing impacts, and protection from dust and rain. The push-button release makes installation and removal smooth and easy.

Once again, a door is provided on the side of this lens hood for filter rotation access. I find the door frequently getting opened inadvertently, especially from the camera being inserted into or removed from a case. I only have slim circular polarizer filters, and I'm not able to rotate them at all through the opening. Even if my filters were rotatable, the amount of rotation possible through the small opening is minimal with many full-width swipes required for the most common rotation amount, the 90° rotation often required when switching the camera from horizontal to vertical orientation. I epoxied the hood window closed on my EF 100-400 L II hood, and plan to do the same with this one.

Standard is for Canon to include a lens case with all L-series lenses, and this one gets the new Canon LZ1328 Lens Case. From the image, you likely figured out that the new part is the color black. This case is well-constructed, quite protective, and with a double-zippered opening, easy to use.

As you likely recognized, the LZ1328 holds only the lens. In the field, it is usually beneficial to have a camera mounted for fast use. With the Canon EOS R5 or EOS R6 mounted, the overall camera and lens length, including the lens cap, is 11.2" (285mm). That means the excellent Think Tank Photo Digital Holster 30 V2.0 is just right for a convenient and compact, yet protective, carrying solution. Note that a lens plate may inhibit fit into this case.

Price, Value, Compatibility

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This lens is rather expensive, and the price will represent a hurdle for non-serious photographers. However, this highly-useful lens performs up to its cost. As a most-used lens, the value is there.

Canon "RF" lenses are compatible with all Canon EOS R-series cameras. Canon USA provides a 1-year limited warranty.

The reviewed Canon RF 100-500mm F4.5-7.1 L IS USM Lens was purchased online-retail.

Alternatives

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Initially, the primary alternative telephoto zoom lens to consider is the excellent Canon EF 100-400mm f/4.5-5.6L IS II USM Lens. Check out the In-Depth: Canon RF 100-500mm F4.5-7.1 L IS USM Lens Compared to EF 100-400mm f/4.5-5.6L IS II USM Lens article for the full details. My advice is to get the RF lens.

Introduction of the Canon RF 200-800mm F6.3-9 IS USM Lens provided a good alternative. The focal length range difference is obviously significant. While the 100-199mm range is welcomed for many uses, including environmental wildlife imagery and portraits, the 501-800mm range (without extenders added to the comparison) holds great advantages, especially for wildlife photography.

The 100-500mm lens wins the image quality comparison, even at wide-open apertures and especially at the wider focal lengths. With the 1.4x mounted, the 100-500 at 700mm is slightly sharper than the 200-800 at 800mm. The 100-500 has slightly less peripheral shading at matching widest available wide apertures and less barrel distortion at the wider shared focal lengths.

The Canon RF 100-500mm F4.5-7.1 L IS USM vs. RF 200-800mm F6.3-9 IS USM Lens comparison shows the 100-500 about 66% as long, narrower, and 24.2 oz (685g) lighter. The 100-500 has a Dual Nano USM AF system vs. Single Nano USM, 77mm filter threads vs. 95mm, a dedicated manual focus ring, a focus distance range switch, and a 0.33x max magnification vs. 0.25x. The 200-800 has a 5.5 stop rated IS system vs. 5.0, but the 100-500's coordinated IBIS rating goes to 6.0 stops. Of course, these CIPA ratings are calculated at the long end of the zoom range, and the 200-800's rating likely matches or exceeds the 100-500's coordinated rating at 500mm.

If the 100-500mm focal length range is adequate for your needs, and you can afford the RF 100-500's moderately higher price, that lens is my recommendation. Otherwise, the 200-800 is the better choice.

A more economical alternative to the RF 100-500 is the Canon RF 100-400mm F5.6-8 IS USM Lens.

The 100-500mm lens easily wins the image quality comparison, especially at the wider focal lengths. The RF 100-500 is sharper (better contrast and resolution) wide open than the RF 100-400 is at any aperture. At equal apertures, the RF 100-500 has less peripheral shading, and it has slightly less geometric distortion as well.

The Canon RF 100-500mm F4.5-7.1 L IS USM vs. Lens RF 100-400mm F5.6-8 IS USM Lens comparison also shows big differences. Smaller size and lighter weight are two major advantages the RF 100-400 holds. The smaller size means smaller filters for the RF 100-400, 67mm vs. 77mm. The RF 100-400 has a higher maximum magnification (0.41x vs. 0.33x) and a .5-stop higher image stabilization rating (5.5 vs. 5), though both lenses are rated to 6 stops with coordinated IBIS. The RF 100-500 has a considerably longer focal length range, has a zoom torque ring, has a focus distance limit switch, and features three IS modes. The RF 100-500 costs more than 4x as much.

Use the site's tools to create additional comparisons.

Summary

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Many referred to 2014 as the "Year of the Lens", and the Canon EF 100-400mm f/4.5-5.6L IS II USM Lens was one of many 2014-announced models. That lens was the hottest, most in-demand model of them all. The Canon EF 100-400mm f/4.5-5.6L IS II is in an elite class of zoom lenses capable of producing prime-grade image quality at all available aperture and focal length settings. Put a useful focal length range into a ruggedly-built, pro-grade lens with fast and accurate AF, effective image stabilization, and impressive image quality, and it is destined to be a popular model. The 100-400 L II quickly became one of my favorite and most-used lenses.

The EF 100-400mm L II USM Lens set the bar high, but the Canon RF 100-500mm F4.5-7.1 L IS USM Lens has easily cleared it. Only six years after the EF 100-400 L II was released, the Canon RF 100-500mm F4.5-7.1 L IS USM Lens arrived on the streets and became the lens to get. Featuring a lighter weight and longer focal length range, this lens surpasses the impressive predecessor in many regards and gained immediate strong popularity. The RF 100-500 immediately became an integral part of my kit. It and I have spent a lot of time together.