Canon RF 100-300mm F2.8 L IS USM Lens Review

Is the Canon RF 100-300mm F2.8 L IS USM Lens the sharpest zoom lens ever? That sounds like a good question for the start of a review.

Photographers love prime lenses for their ultra-wide apertures, compact size, modest weight, and superior image quality. The Canon RF 100mm F2.8 L Macro IS and Canon EF 300mm f/2.8L IS II Lenses are two excellent examples of impressive performing prime lenses.

What if you could have the optical performance of both lenses in a single, professional-grade lens that includes the same max aperture opening and all the missing focal lengths between 100mm and 300mm? And, what if that telephoto zoom lens was compatible with extenders and matched the optical performance of the 300mm prime lens with extenders? What if that lens weighed only 10.5 oz (300g) heavier and had a fixed size (and balance) measuring only 2.9" (40.4mm) longer than the 300mm f/2.8 prime?

The Canon RF 100-300mm F2.8 L IS USM Lens makes that dream a reality. The RF 100-300mm F2.8 is an extremely high-performance professional-grade telephoto zoom lens.

Focal Length Range

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Focal length range is the first consideration for zoom lens selection. Focal length drives subject distance choices (or meets distance-related requirements), which also determines perspective.

While it has other uses, the Canon RF 100-300mm F2.8 L IS USM Lens will primarily be used for photographing people.

The RF 100-300 is rather heavy as a general-purpose portrait lens, but it has the ideal angle of view range for pleasing perspectives, including from full-body portraits, including full horse bodies, to tight headshots. This lens's outstanding background blur capability separates its portrait results from the crowd.

The 100-300mm range is the perfect choice for photographing people participating in events. Think weddings, parties, stage performances, etc. Fashion is another great use for this range.

Most photojournalists primarily photograph people, and this lens is optimal for their pursuits.

Photographing people competing is perhaps the best use for the 100-300mm range, and this lens's wide aperture over the entire range makes it ideal for indoor sports. This range is great for court sports (tennis, volleyball, basketball, etc.), rink sports (hockey, for example), swimming, gymnastics, track and field, BMX, motorsports, etc.

The 300mm full-frame angle of view is rather wide for large field sports such as soccer, but when the subject approaches the sidelines or goal line, this range is the perfect supplement to the longer focal lengths.

Most wildlife photographers will prefer angles of view narrower than 100-300mm, but most using the longer lenses also appreciate a shorter zoom lens to capture environmental images and for large and close subject needs. The 100-300mm range is a great complement to a 400mm, 500mm, or 600mm lens.

The RF 100-300 performs exceedingly well with extenders, and adding a 1.4x or 2x extender creates a focal lengths range that nicely covers wildlife and large field sports requirements.

Videographers will find the 100-300mm range ideal for the same uses as still photographers.

Here are focal length range examples that include 100-300mm:

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APS-C sensor format cameras utilize a smaller image circle than full-frame models, framing a scene more tightly. 1.6x is the Canon angle of view equivalence multiplier, and on an APS-C camera, this lens provides an angle of view equivalent to a 160-480mm lens on a full-frame camera.

The significantly narrower angle of view makes this lens suitable for sports on larger fields and for wildlife while diminishing the portrait usefulness.

Max Aperture

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This lens's f/2.8 aperture is extremely useful and differentiating in this lens, for both image quality and image appearance. No other Canon zoom lens longer than 200mm offers the f/2.8 aperture.

The light provided by wide aperture lenses permits sharp images of subjects in motion, with the camera handheld in lower light levels, and with lower (less noisy) ISO settings. In addition, increasing the aperture opening provides a shallower DOF (Depth of Field) that creates a stronger, better subject-isolating background blur (at equivalent focal lengths). Often critical is the improved low-light AF performance availed by a wide-aperture lens.

A wide aperture's disadvantages are related to, significantly in this case, increased lens element size, including larger overall size, heavier weight, and higher cost. This is not a small or light lens, but it is small and light for its specs.

These examples illustrate the maximum blur this lens can create:

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This fawn volunteered to illustrate the 300mm background blur.

The background is a significant percentage of many images, and when the background is not complementary to the subject (or even distracting), blurring it away is highly advantageous. That capability is in this lens's skill set.

Image Stabilization

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Further aiding the handholdableness of this lens is optical image stabilization.

The longer the focal length, the larger subject details (captured at the same distance) are rendered, and the more still the camera must be held to avoid subject details crossing imaging sensor pixels, the source of image blur. Image stabilization is an extremely valuable feature in any lens and an especially valuable feature in a telephoto lens.

Another image stabilization benefit is its aid to AF precision, as the camera's AF system can produce improved focus precision if the image it sees is stabilized.

The Canon RF 100-300mm F2.8 L IS USM Lens's image stabilization rating is 5.5 stops, up from 4.0 stops in the EF 300mm f/2.8 L II, and 6.0 stops when used on a camera with IBIS (Coordinated IS).

"Coordinated IS control has made it possible to accurately detect and correct shaking information across the camera and lens. This is based on the gyro sensors on both the camera and lens, in addition to the camera’s acceleration sensor and live view images. To detect low-frequency swaying, such as movement of the entire body when shooting by handheld, we gave the RF100-300mm F2.8 L IS USM a design that is more resistant to low-frequency sway."

"In particular, with the RF mount, the communication speed between the camera body and the lens has been significantly improved, and the amount of information has increased dramatically compared to the EF Mount. Information on focus, zoom, aperture, and lens aberrations, as well as IS information, are instantly exchanged." [Yumi Toyoda, Electronics/Firmware Design, Canon, Inc.]

The IS difference seen in the viewfinder is significant, and image stabilization is useful for stabilizing the viewfinder, aiding in optimal composition. Handheld movie recording quality is significantly improved by image stabilization.

While IS is active, drifting of framing is not an issue, and the viewfinder view is well-controlled, not jumping at startup/shutdown and permitting easy reframing. A faint, scratchy whir is heard only by an ear a couple of inches from the lens.

Along with the standard Mode 1 (general-purpose), Mode 2 (for panning with a subject, one axis of stabilization is provided), and Mode 3 are available. Mode 3 is useful for tracking erratic action. In this mode, image stabilization is active and ready for use the moment the shutter releases, but actual stabilization is not in effect until that precise time. As a result, the view seen through the viewfinder is not stabilized, allowing an erratically moving subject to be tracked without fighting against image stabilization trying to stop the motion. Mode 3 is designed to detect panning motion, and when detected, the lens will only apply stabilization at right angles to the direction of the detected movement (like Mode 2).

The On/Off switch on the lens controls both the lens and in-body image stabilization systems simultaneously.

Note that this IS system rattles when not mounted to a powered-on camera. This rattle is not a concern.

When you need/want to leave the tripod behind, IS is there for you, helping to ensure sharp images and adding significant versatility to this lens. When vibrations, such as those caused by wind, are present when using a tripod, IS can save the day, enabling image capture not otherwise, possible.

Image Quality

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Back to the "Is the Canon RF 100-300mm F2.8 L IS USM Lens the sharpest zoom lens ever?" question. This is another expensive big white Canon lens, and that combination immediately sets the expected image quality level extremely high, but this lens is crazy sharp.

Let's start the image quality evaluation with a look at the MTF charts.

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The black lines indicate contrast, and the blue lines show resolution. The solid lines are sagittal, and the dashed lines are meridional. The higher, the better, and that comparison tells a story.

As mentioned at the beginning of this review, the Canon RF 100mm F2.8 L Macro IS and Canon EF 300mm f/2.8L IS II Lenses are outstanding performers. That the Canon RF 100-300mm F2.8 L IS USM zoom Lens is as sharp as these lenses is remarkable.

I looked forward to proving this expectation.

The lab's test chart quickly put an end to the questioning, and describing the optical quality of an ultra-high-performing lens such as this one is easy. At f/2.8, this lens produces extremely sharp image quality from full-frame corner to full-frame cover over the entire focal length range. Let's go outside.

Here are a series of center-of-the-frame 100% resolution crop examples. These images were captured using an ultra-high resolution Canon EOS R5 with RAW files processed in Canon's Digital Photo Professional (DPP) using the Standard Picture Style with sharpness set to 1 on a 0-10 scale.

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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Factor into these results that telephoto lenses magnify heat waves created on clear sky days and look for details in the plane of sharp focus for your evaluations. I didn't waste your bandwidth by sharing the f/4 or narrower results — they look the same as the crazy sharp f/2.8 results.

Check out this 100% crop of a white-tailed deer fawn's eye.

That 300mm f/2.8 performance is impressive.

Next, we'll look at a series of comparisons showing 100% resolution extreme top left corner crops captured and processed identically to the above center-of-the-frame images. The lens was manually focused in the corner of the frame to capture these images.

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Again, heat waves and shallow depth of field must be accounted for when viewing these results.

This lens does not exhibit focus shift, the plane of sharp focus moving forward or backward as the aperture is narrowed (residual spherical aberration or RSA).

A lens is expected to show peripheral shading at the widest aperture settings when used on a camera that utilizes its entire image circle. From 100mm through 200mm, expect a mild just-under 2 stops of shading in the corners, increasing to about 2.5 stops at 300mm.

At f/4, the peripheral shading is about 1 stop deep in the corners, and except at 300mm, the shading is confined to the extreme periphery of the frame. Vignetting is extremely low at f/5.6.

APS-C format cameras using lenses projecting a full-frame-sized image circle avoid most vignetting problems. In this case, the about half of a stop of corner shading showing in 100-200mm corners at f/2.8 will seldom be visible, and the about 1 stop of shading at 300mm might show in select images, primarily those with a solid color (such as a blue sky) in the corners.

One-stop of shading is 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 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 shown in our vignetting test tool to determine how your images will be affected.

Lateral (or transverse) CA (Chromatic Aberration) refers to the unequal magnification of all colors in the spectrum. 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 to avoid this aberration in the first place.

This color misalignment can be seen in the site's image quality tool, but let's also look at a set of worst-case examples. The images below are 100% crops from the extreme top left corner of Canon EOS R5 frames showing diagonal black and white lines.

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Only black and white colors should be present in these images, with the additional colors indicating the presence of lateral CA, primarily at 100mm where the amount is modest.

A relatively common lens aberration is axial (longitudinal, bokeh) CA, which causes non-coinciding focal planes of the various wavelengths of light. 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 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.

The examples below look at the defocused specular highlights' fringing colors in the foreground vs. the background. The lens has introduced any fringing color differences from the neutrally colored subjects.

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These results show only minor color separation, reflecting good performance.

Bright light reflecting off lens elements' surfaces may cause flare and ghosting, resulting in reduced contrast and sometimes interesting, usually destructive visual artifacts. The shape, intensity, and position of the flare and ghosting effects in an image are variable, dependent on the position and nature of the light source (or sources), selected aperture, shape of the aperture blades, and quantity and quality of the lens elements and their coatings. Additionally, flare and ghosting can impact AF performance.

To avoid flare and ghosting, this lens features Canon's SSC (Super Spectra Coating), and ASC (Air Sphere Coating), an ultra-low refractive index coating consisting of air and silicon dioxide, is utilized on three elements. However, the high 23-element design increases the challenge, and this lens produced moderate flare and ghosting effects at narrow apertures in our standard sun in the corner of the frame flare test, a test that tends to favor wider angle lenses.

Flare effects can be embraced or avoided, or removal can be attempted. Unfortunately, removal is sometimes challenging, and in some cases, flare effects can destroy image quality.

Two lens aberrations are particularly evident in 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 that can be oriented either away from the center of the frame (external coma) or toward the center of the frame (internal coma). The 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). This aberration can produce stars appearing to have wings. 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 images captured at f/2.8.

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While the stars in these samples are not rendered as perfectly round pinpoints of light, they are close to that desired outcome, with the RF 100-300 outperforming most other lenses in this regard.

This lens has minor barrel distortion at 100mm. The barrel distortion quickly resolves with focal length increase, transitioning into minor pincushion distortion at 300mm.

With telephoto focal lengths and a wide max aperture, this lens can create a strong background blur.

"With a 300mm f/2.8 lens, many users are concerned with the beauty of the bokeh, as well as the large aperture. We designed the lens to thoroughly reduce chromatic aberration and preserve the soft bokeh effect. [Masato Katayose, Optical Design, Canon, Inc.]

Due to the infinite number of variables present among available scenes, assessing the bokeh quality is challenging. Here are some f/11 (for diaphragm blade interaction) examples.

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The first set of examples, 100% crops, shows defocused highlights filled rather smoothly and shaped relatively round.

Full images reduced in size and looking nice are shown in the second set of examples.

Except for a small number of specialty lenses, the wide aperture bokeh in the frame's corner 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 frame's corner, the shape is not round. That is the shape we're looking at here.

The 100mm results show the upper-left quadrant, and the 200mm and 300mm results are full images captured at an angle.

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While there is truncation showing these images, it is isolated to deep in the corners. As the aperture narrows, the entrance pupil size is reduced, and the mechanical vignetting diminishes, making the corner shapes rounder. At f/4, the truncation is mostly resolved.

A 9-blade count diaphragm will create 18-point sunstars (diffraction spikes) from point light sources captured with a narrow aperture. Generally, the more a lens diaphragm is stopped down, the larger and better shaped the sunstars tend to be. Wide aperture lenses tend to have an advantage in this regard, though this lens doesn't produce the most amazing star effects.

The example above was captured at f/16.

The design of this lens is illustrated below.

A Fluorite element, 4 UD elements, and an Aspherical element, along with the SSC (Super Spectra Coating) and ASC (Air Sphere Coating), are featured in this lens.

"We used fluorite and doublet UD lenses to reduce the chromatic aberration for each lens group to achieve high image quality for the RF100-300mm F2.8 L IS USM, especially at the telephoto end. Fluorite, with its low specific gravity, contributes to reducing weight. We used three UD elements near the diaphragm, reducing chromatic aberration at the center of the image. Another point is that we used a large diameter GMo aspheric lens for the final lens group. This was a significant factor in reducing the number of lenses and achieving high image quality." [Masato Katayose, Optical Design, Canon, Inc.]

"In lens processing, we made full use of our expertise, including high-precision processing technology for large aperture aspheric lenses at the Utsunomiya Plant. Stabilizing the surface accuracy of thinned concave lenses to near the processing limit significantly contributed to reducing the weight and improving the image quality. [Ken Uraba, Manufacturing Technology, Canon, Inc.]

The bottom line is that the Canon RF 100-300mm F2.8 L IS USM Lens produces outstanding image quality.

Focusing

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"The RF100-300mm F2.8 L IS USM features two linear-drive type nano USMs. The nano USMs improve the agility of reciprocating movements, and the mechanical structure of the focus drive has been simplified, which contributes to weight and size reduction." [Nobuyuki Nagaoka, Mechanical Design, Canon, Inc.]

All four hooves off the ground indicate that this horse is moving fast. That speed is no problem for this lens. It internally focuses extremely fast, with high precision and low audibility (light clicks and shuffling). Aided by the wide aperture, this lens focuses in relatively low-light environments.

Nano USM lenses focus smoothly, making video focus distance transitions easy on the viewer's eyes. Even the lens's aperture changes are quiet and smooth.

The RF super-telephoto lenses include a Focus Preset feature. Set the Focus Preset to a specific distance. When your shooting needs require that distance, press the button on the right side of the lens near the mount just with a grip hand fingertip, and the lens will automatically adjust to the preset distance.

A 2-position focus limiter switch allows focusing distances to be limited to a subset of this lens's focus distance range. In addition to the full range, a restricted limit of 19.7' (6m) - ∞ can be selected for improved focus lock times and reduced focus hunting.

Four autofocus stop buttons in the black ring near the objective lens allow autofocus to be temporarily stopped. I use Servo (continuous) focusing mode for shooting sports but sometimes shoot focus-and-recompose images such as portraits during the event. The autofocus stop feature makes it easy to obtain focus lock, turn off autofocus, and recompose.

Another excellent use for this feature is when an image has been captured with suboptimal framing. Simply press a focus stop button and then capture sufficient images to stitch together during post-processing. Of course, switching the lens to manual focus mode also works for these techniques.

The "PF" or Power Focusing mode included on Canon's larger RF lenses was omitted on this lens.

FTM (Full Time Manual) focusing is supported in AF mode while in One Shot Drive Mode, but the shutter release must be half-pressed for the focus ring to be enabled. Note that FTM does not work if electronic manual focusing is disabled in the camera's menu (if this option is present). The lens's switch must be in the "MF" position and the camera meter must be on and awake for conventional manual focusing to be available.

The review lens does not exhibit parfocal-like behavior, but it is close to being so. Though subjects focused on at 300mm remain in sharp focus throughout most of the focal length range, they become slightly blurred at 250mm due to the plane of sharp focus moving rearward. The 100% crops below illustrate this behavior.

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Note the sharpness of these f/2.8 results.

The RF 100-300's rubber-ribbed focus ring is appropriately sized for this lens's design and has light resistance. The 60° full-extent rotation at 100mm and 460° at 300mm (200° if turned fast) adjusts focusing a bit fast for precise manual adjustment, and adjusting in small steps detracts from the manual focus experience.

It is normal for the scene to change size in the frame (sometimes significantly) as the focus is pulled from one extent to the other. This effect is focus breathing, a change in focal length resulting from a change in focus distance. Focus breathing impacts photographers intending to use focus stacking techniques, videographers pulling focus (without movement to camouflage the effect), and anyone critically framing while adjusting focus.

This lens produces a minor change in subject size through a full-extent focus distance adjustment at the wide end and a modest change at the long end.

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Big white Canon telephoto lenses do not typically have short minimum focusing distances. This lens focuses down to 70.9" (1800mm) throughout the focal length range, generating a mediocre 0.16x maximum magnification spec at 300mm.

Model	Min Focus Distance "(mm)		Max Magnification
Canon RF 70-200mm F2.8 L IS USM Lens	27.6	(700)	0.23x
Canon RF 100-300mm F2.8 L IS USM Lens	70.9	(1800)	0.16x
Canon RF 100-500mm F4.5-7.1 L IS USM Lens	35.4	(900)	0.33x
Canon EF 200-400mm f/4L IS USM Lens	78.7	(2000)	0.15, 0.21x
Canon RF 100mm F2.8 L Macro IS USM Lens	10.2	(260)	1.40x
Canon RF 400mm F2.8 L IS USM Lens	98.4	(2500)	0.17x
Canon RF 600mm F4 L IS USM Lens	165.4	(4200)	0.17x

At 100mm, a subject measuring approximately 22.3 in. x 14.8" (566 × 376mm) fills a full-frame imaging sensor at this lens's minimum MF distance. At 300mm, an 8.7 x 5.9" (222 × 149mm) subject does the same.

Though taken beyond the minimum focus distance, this fawn image shows a close-focus example.

Need a shorter minimum focus distance and higher magnification? Mount an extension tube behind this lens to modestly decrease and increase those respective numbers. 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 function normally.

As of review time, Canon does not offer RF mount-compatible extension tubes, but third-party options are available.

Better still, get an extender.

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Extenders / Teleconverters

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The Canon RF 100-300mm F2.8 L IS USM Lens is compatible with the Canon RF 1.4x Extender and the Canon RF 2x Extender.

With the 1.4x behind it, this lens becomes a 140-420mm f/4 IS lens. With the 2x mounted, it becomes a 200-600mm f/5.6 IS lens. Having 100-300mm f/2.8, 140-420mm f/4, and 200-600mm f/5.6 IS lenses available with a quick extender change is extremely valuable, adding greatly to this lens's versatility, and this lens's outstanding optical performance means sharp with-extender images.

Weather sealing and image stabilization remain included and effective. The lens's native minimum focusing distance is retained with extenders in use, and that means the maximum magnification value is multiplied by the extender's multiplier, a significant improvement.

With the RF 1.4x behind the RF 100-300 L and a wide-open aperture selected, image sharpness is barely impacted. Let me make this clear — that is exceptional performance for any lens and outstanding performance for a zoom lens. The RF 1.4x adds a slight amount of barrel distortion, offsetting the slight pincushion distortion at 300mm, but it does not notably affect lateral CA.

The image sharpness hit with the 2x extender is stronger than with the 1.4x. However, this combination again performs exceptionally well. The 2x increases lateral CA noticeably and barrel distortion slightly.

I seldom recommend or use 2x extenders due to their impact on image quality, but I was so impressed by this combination's performance that I went birding with it.

The hummingbird image above is 600mm cropped modestly, and 339mm was used for the great blue heron image below.

Let's take a closer look at the 2x image quality. The next two 100% crop images were processed the same as the sharpness test results shared earlier in the review.

This frog in the shade was cropped from a 600mm image.

Look at the detail in the frog's eye.

The image below was cropped from the 339mm ISO 400 heron image shared just above.

The with-extender autofocus performance is excellent — like the extender is not there.

Why doesn't the Canon RF 100-300mm F2.8 L IS USM Lens have a built-in extender like the Canon EF 200-400mm f/4L IS USM Lens? Yuriyo Asami, Product Planning, Canon, Inc., answers that question:

"We also considered a lens with a built-in extender, but we decided to achieve 3x zoom without a built-in extender as it offered the best balance between size, performance, and spec."

Design & Features

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Canon's big white super-telephoto lenses are among the most elite lenses available and represent the Canon L Series' best. Professionals expect these lenses to deliver the ultimate performance in the most adverse environments.

Expect to immediately feel the ultra-high construction quality when you pick up this lens.

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"... We pursued an elegant and integrated design for the camera body and lens." [Ken Uraba, Manufacturing Technology, Canon, Inc.]

Notable is that this lens has a fixed size that maintains balance throughout the range, a feature especially loved by videographers.

Also notable is the control ring. This inclusion is not notable for RF lenses in general, as most have them. However, this is the first big white L lens to get the ring.

The control ring is configurable for fast access to camera settings, including aperture, shutter speed, ISO, exposure compensation, AF area, and more. 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 click stop removal service for this ring (at a cost). The control ring is separated from the focus ring by an adequate amount of space and, along with a texture difference, it is easy to tactilely find the ring you want (though the grip ring further out the barrel is not so texturally different).

This lens has numerous switches. The generous spacing between each switch makes it easy to locate the desired option from memory, and the small ridges on each switch are raised just enough for easy use, even with gloves on. A firm pressure is needed to move each switch, and a click confirms and holds the position.

The color of this lens deserves additional attention. Heat gain, especially uneven heat gain, can cause problems for a lens's optical performance, and big lenses have a lot of surface area to catch sunlight. Canon has chosen white paint to avoid as much heat gain as possible, and the new paint formulation better shields the lens from heat than the previous paint did.

"Infrared reflective pigments with high reflectance and titanium oxide lens barrel coating with silica provide excellent UV weather resistance and heat reduction." [Canon]

"For the white thermal barrier coating on the surface, we took color and texture into account, and we used the scratch-resistant, uneven, leather-tone coating, also used in the RF400mm F2.8 L IS USM and other lenses. As a result, we have achieved high thermal insulation and durability." [Masaaki Igarashi, Design, Canon, Inc.]

This is a weather-sealed lens. Many outdoor events are held regardless of the weather, and the photographers required to cover them are forced to deal with the weather. While I recommend a rain cover when wet weather is expected, it is the unexpected that can be a problem. I've used Canon weather-sealed super-telephoto lenses in some rather heavy rain with no ill effects. In addition to being sealed from moisture, dust is another hazard this lens keeps out.

A fluorine coating is applied for easier cleaning and for preventing dust and drips from adhering in the first place.

At 5.84 lbs (2.65kg), this lens can easily be handheld for reasonable periods. Still, this is a relatively heavy lens. Those familiar only with smaller lenses, such as the Canon RF 70-200mm F2.8 L IS USM Lens, will require a bit of acclimating, but that acclimation does happen.

The size of this lens garners attention. You look like you belong in some venues, and you stand out in others. You'll get over the latter. Regarding the former, this lens can be a ticket to access. Lenses like this one have garnered entrance to locations in venues that I would otherwise have been restricted from.

Model	Weight oz(g)		Dimensions w/o Hood "(mm)		Filter	Year
Canon RF 70-200mm F2.8 L IS USM Lens	37.8	(1070)	3.5 x 5.7	(89.9 x 146.0)	77	2019
Canon RF 100-300mm F2.8 L IS USM Lens	93.5	(2650)	5.0 x 12.7	(128.0 x 323.4)	112	2023
Canon RF 100-500mm F4.5-7.1 L IS USM Lens	48.2	(1365)	3.7 x 8.2	(93.8 x 207.6)	77	2020
Canon EF 200-400mm f/4L IS USM Lens	127.8	(3620)	5.0 x 14.4	(128.0 x 366.0)	DI 52	2013
Canon RF 100mm F2.8 L Macro IS USM Lens	25.8	(730)	3.2 x 5.8	(81.5 x 148.0)	67	2021
Canon EF 300mm f/2.8L IS II USM Lens	83.0	(2350)	5.0 x 9.8	(128.0 x 248.0)	DI 52	2011
Canon RF 400mm F2.8 L IS USM Lens	102.0	(2890)	6.4 x 14.4	(163.0 x 367.0)	DI 52	2021
Canon RF 600mm F4 L IS USM Lens	109.1	(3090)	6.6 x 18.6	(168.0 x 472.0)	DI 52	2021

For many more comparisons, review the complete Canon RF 100-300mm F2.8 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 300mm f/2.8L IS II USM Lens
Canon RF 100-300mm F2.8 L IS USM Lens
Canon EF 200-400mm f/4L IS USM Lens
Canon RF 400mm F2.8 L IS USM Lens

Remember that the EF mount lenses require a Canon Mount Adapter EF-EOS R for use on a Canon EOS R-series camera, and the adapter slightly increases the length of those lenses.

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

Use the site's product image comparison tool to visually compare the Canon RF 100-300mm F2.8 L IS USM Lens to other lenses.

At announcement time, I fully expected that this lens would use 52mm drop-in filters like all of Canon's other big white lenses. That was an incorrect assumption, and there was a good reason for this omission.

"The drop-in filter was omitted by pursuing a compact size, reduced weight, and an optical design where the lens group is placed close to the mount. As a result, the large diameter of the lens barrel, which was a concern in terms of lens strength, has been removed, and the thinner outer barrel also contributed to further weight reduction. [Makoto Hayakawa, Chief of Development/Mechanical Design, Canon, Inc.]

Still, this lens can utilize filters — conventional threaded front filters. Unfortunately, 112mm filters are scarce, large, and expensive.

The tripod foot is nicely rounded, making the lens comfortable to handhold and carry. With the foot resting in the hand, the focus and zoom rings are readily accessible to the fingers. The height of the foot aids in supporting the lens with an elbow against the body.

This foot has 1/4" and 3/8" threaded inserts. A Wimberley P40 Lens Plate permits quick attachment to Arca-Swiss compatible monopod and tripod head clamps. Mounting with two screws is important to prevent the plate from twisting, but most lens plates will require a 3/8"-16 to 1/4"-20 Reducer Bushing in the foot's larger threaded insert. The bushings are inexpensive, and it seems Canon could easily have included one in the box. Much better would have been to machine the needed Arca-Swiss dovetail grooves into the foot, as some other lens manufacturers are doing.

Replacing the Canon tripod foot with a Wimberley AP-601 or Really Right Stuff Tripod Foot is popular and my preference.

The tripod collar is exceptionally smooth and provides light click stops at 90°-degree rotations. While the click stops cause a small bump during rotation (such as tilting a monopod while panning with a subject), I prefer to have the click stops assisting me with finding center, aiding in keeping a camera level.

While this lens can be handheld for reasonable periods, you will still appreciate having support under the lens for longer periods of use (and for stabilizing the view). Avoiding future shoulder issues may not seem important today, but I assure you that you will one day appreciate having cared for your body during youth. Keep your elbows in and down.

I suggest using a strong ball head (such as the Really Right Stuff BH-55 for tripod mounting this lens. Much better (safer, easier) is to use a lens of this size on a gimbal-style head such as the Wimberley WH-200-S Sidemount Head, Wimberley Tripod Head II, or Really Right Stuff PG-02 MK2 Pano-Gimbal Head.

A smaller monopod foot is an optional accessory.

As first seen on the EF 400 IS II, the RF 400 F2.8 has a Kensington-type wire security lock under the tripod collar lock knob cap.

The included ET-124 lens hood is rigid, rather light, and large, offering the front lens element excellent protection from bright light, impact, and the elements. Designed to facilitate the 100mm angle of view, the ET-124 is significantly smaller than the EF 300mm F2.8 L II IS lens's designed-only-for-300mm ET-120. While the ET-124 hood is quite rugged, protect it as a replacement will cost as much as a nice lens.

Instead of the flexible woven nylon lens cap that wraps around the reversed hood found on Canon's other big white lenses, the RF 100-300 has a plastic center and side pinch lens cap as typically found on smaller lenses with front filter threads. Attaching to the 112mm filter threads means that the E-112 cap is large.

The included padded lens strap can be attached to the tripod ring, an attachment point that allows the camera to be rotated without the neck strap following the rotation (causing strangulation).

The Canon LS100–300 sling-style (single strap) shoulder lens case is included. This attractive nylon case is relatively compact and lightweight, well-padded, easy to use with smooth-functioning zippers and large pulls, and has a round molded-plastic bottom that keeps it upright on a flat surface.

A thin 7" (178mm) tall by 6" (152mm) wide zippered pocket and a pair of strap attachment points are provided on both sides of the case. The shoulder strap is padded and strong, and breathable padding is provided on the strap's case side, adding to the shoulder-carrying comfort. The convenient hand strap on top is also strong, with breathable padding ensuring that grip is not lost. Four hook-and-loop-adjustable pads are provided for interior use.

At review time, the Think Tank Photo StreetWalker Pro is my preferred carry case for this lens mounted to a camera, and the Think Tank Photo StreetWalker (not Pro) also works well. For a more compact and faster-to-use solution, consider the Think Tank Photo Digital Holster 150. A friend shares that an EOS R3-mounted RF 100-300 with a UV filter installed, the hood reversed, and tripod foot angled just fits in this case.

Price, Value, Compatibility

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While the Canon RF 100-300mm F2.8 L IS USM Lens delivers exceptional image quality, it has a high price tag.

When the versatility of this lens is considered, the price becomes more palatable. For example, an event photographer may need to simultaneously carry 24-70mm, 70-200mm, and 300mm f/2.8 lenses, each on a body ready for immediate use. The RF 100-300 potentially replaces the 70-200 and 300 and eliminates a camera (and switching cameras during the action) or permits an additional lens to be carried, such as a 15-35. With extenders available, the RF 100-300 can also replace the functionality of the EF 200-400mm F4 L IS lens and EF 400mm F4 DO IS II.

Those who require the ultimate image quality will find this lens easily worth its price, though few casual photographers will choose to afford this lens.

Fortunately for those making this purchase, quality lenses hold their value. While the overall cost of ownership for these lenses can vary greatly, a big white Canon telephoto lens historically can be sold for a significant percentage of the purchase price. The concept of buying this lens to photograph a child's high school sports career and later selling it to help fund their college education seems logical.

If the price makes the RF 100-300mm F2.8 unobtainable for you, consider renting one for your special events. Consider getting other parents to share in the rental expense in exchange for photos of their kids participating in sports.

As expensive as this lens is, you get what you pay for. Also, consider that price is a barrier to entry, meaning skilled photographers with this lens have a competitive advantage that will not be surmounted by the masses with a camera.

As an "RF" lens, the Canon RF 100-300mm F2.8 L IS USM Lens is compatible with all Canon EOS R-series cameras, including full-frame and APS-C models. Canon USA provides a 1-year limited warranty.

The reviewed Canon RF 100-300mm F2.8 L IS USM Lens was online-retail sourced.

Alternatives

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While Canon does not have a direct alternative or predecessor for the RF 100-300mm F2.8 L IS Lens, there are other lenses to consider. First up is the Canon RF 70-200mm F2.8 L IS USM Lens.

Featuring an extending design, the RF 70-200 is a remarkably compact and lightweight lens for its specs. This lens also delivers remarkably sharp images, leaving little room for the RF 100-300 to surpass it.

In the image quality comparison, the RF 100-300 takes a slight advantage,' primarily in the corners and in the center at 200mm. The 70-200 shows less flare and ghosting, but it has significantly more peripheral shading at most shared focal lengths.

The Canon RF 100-300mm F2.8 L IS USM Lens vs. RF 70-200mm F2.8 L IS USM Lens comparison shows the huge size and weight difference required to shift the focal length range from 70-200mm to 100-300mm. The 100-300 is about 2.5x heavier and 2.2x longer than the 70-200. The 70-200 uses 77mm filters vs. 112mm and has a 0.23x maximum magnification vs. 0.16x.

The 100-300's IS system is rated for 5.5 stops of assistance vs. 5.0, but the 70-200's IS system is rated for 7.5 stops of coordinated assistance vs. 6.0. The 100-300 has the focus preset feature and AF stop buttons.

The 70-200mm f/2.8 lens class usually provides the longest affordable f/2.8 focal length, and the RF 100-300 does not change that scenario. However, 300mm is considerably longer than 200mm (and the background blur it can create is also considerably stronger), and the 100-300 is compatible with extenders, significantly increasing the focal lengths available. The RF 100-300mm F2.8 lens is nearly 3.5x more expensive than the RF 70-200mm F2.8 Lens.

The 300mm f/2.8 class lens model has not yet arrived in the Canon RF Lens lineup, and the RF 100-300mm F2.8 L IS Lens may be the reason for a permanent omission of that option. That said, the EF lineup has an outstanding 300mm f/2.8 option, the EF 300mm f/2.8L IS II USM Lens. This lens's image quality is stellar, and based on the MTF charts, the RF 100-300 was expected to match it.

The image quality comparison shows this expectation met, even with a 2x mounted (the zoom has slightly more lateral CA). The prime lens has less peripheral shading and slightly less geometric distortion than the zoom lens at 300mm.

The Canon RF 100-300mm F2.8 L IS USM Lens vs. EF 300mm f/2.8L IS II USM Lens comparison shows the zoom lens weighing 10.5 oz (300g) more and measuring 3.0" (75.4mm) longer. The basic RF mount adapter behind the prime lens uses 1" (24mm) and 4 oz (110g) of that difference. The prime lens uses 52mm drop-in filters vs. 112mm threaded filters. The zoom lens has 5.5 stop rated IS vs. 4.0.

The RF 100-300 is priced about 50% higher than the EF 300. To most professional and serious amateur photographers, the zoom range will be worth considerably more than that difference.

The Canon EF 200-400mm f/4L IS USM Lens is currently Canon's other fixed-max-aperture, non-extending, big white zoom lens, and mounting a 1.4x extender behind the RF 100-300 creates a rather similar focal length range at the same aperture.

The 100-300 is slightly sharper in the center in the native range overlap, and impressively, about equivalent with a 1.4x in place (420mm vs. 400). At 600mm, the 100-300 is slightly sharper than the 200-400 at 560mm using the built-in 1.4x, but with more lateral CA. Here is the image quality comparison between these lenses.

The 100-300 has stronger peripheral shading at 200mm and 300mm and slightly more geometric distortion, and the 200-400 shows stronger flare effects and ghosting.

The Canon RF 100-300mm F2.8 L IS USM Lens vs. EF 200-400mm f/4L IS USM Lens comparison shows the 200-400 considerably heavier and modestly longer, especially with an RF mount adapter behind it. The 200-400mm lens uses 52mm drop-in filters vs. 112mm threaded filters. In addition to having a built-in 1.4x extender, the 200-400 is compatible with external extenders, giving it significantly longer focal lengths, though an image quality price is paid. The RF 100-300 is considerably less expensive.

It doesn't make much sense to consider the prime lenses sharing the wider focal lengths available in the RF 100-300mm as direct alternatives due to their vastly smaller size, lighter weight, and lower price. If you need only 100mm, get the Canon RF 100mm F2.8 L Macro IS USM Lens.

Still, it is interesting to compare the zoom lens to the prime lens from an optical performance standpoint. In the image quality comparison, the zoom lens is slightly sharper in the center of the frame. The zoom lens has less peripheral shading, and the prime lens shows less flare and ghosting. At 100mm, the zoom lens has slight barrel distortion, and the prime lens has slight pincushion distortion.

Use the site's tools to create additional comparisons.

Here are a few words about the RF 100-300 from my friend Rudy Winston of Canon USA.

Summary

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I had over 5,000 images from the RF 100-300mm Lens when I finally put it down to finish this review. New uses for the lens keep showing up. This extraordinary-performing lens is extremely useful, and the results are addicting. I added the RF 100-300 to my kit.

"When designing something completely new, you are bound to come across obstacles, and it makes you think, "I see; that is why this hasn't been done yet." With the RF100-300mm F2.8 L IS USM, we achieved this new specification through gradual advancements in technology and clearing one obstacle at a time." [Makoto Hayakawa, Chief of Development/Mechanical Design, Canon, Inc.]

The Canon RF 100-300mm F2.8 L IS USM Lens brings us a new level of zoom lens performance.

This lens is a superb choice for chasing people and especially people in action. Add an extender, and this lens becomes a great choice for wildlife, especially for capturing wildlife videos.