Canon RF-S 18-45mm F4.5-6.3 IS STM Lens Review

The Canon RF-S 18-45mm F4.5-6.3 IS STM Lens is all about providing the most-used general-purpose focal length range in a diminutive, ultralight, low-cost package.

The RF-S 18-45 and the simultaneously announced Canon RF-S 18-150mm F3.5-6.3 IS STM initiated the Canon's RF-S lens lineup. These lenses were introduced beside Canon's first APS-C imaging sensor format RF lens mount camera models, the Canon EOS R7 and Canon EOS R10.

While RF-S lenses function normally on all Canon EOS R-series cameras, they provide an APS-C-sized image circle. Full-frame imaging sensor camera models automatically adjust to the 1.6x narrower angle of view availed by this image circle, and this lens has merit for use on full-frame camera models.

The RF-S 18-150 shares the optical formula and much of the physical design of the Canon EF-M 18-150mm f/3.5-6.3 IS STM Lens, so it would seem logical for Canon to utilize the EF-M 15-45mm f/3.5-6.3 IS STM Lens design for the compact RF-S general-purpose lens option. That did not happen, and the RF-S 18-45 features a brand new design.

A new lens design promises the latest technology and optical formula, raising optimism for higher performance.

Focal Length Range

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A lens's focal length or focal length range is typically included at the beginning of a lens product name for a good reason. Focal length is the first aspect to consider for lens selection. Focal length drives subject distance choices, which determine perspective.

The 18-45mm APS-C zoom focal length range (angles of view equivalent to a full-frame 28.8-72mm lens) covers what I consider the most important range for a general-purpose lens.

As that designation suggests, such a lens is selected for a wide range of uses. This lens gets mounted to the camera in case a need arises and gets selected when needs are to be searched for. This is the type of lens you can take when you are not sure which focal lengths you will need, and usually, it will be the right choice.

The general-purpose focal length range is optimal for photographing people. It is ideal for portraits, weddings, parties, events, documentaries, interviews, lifestyle, theater, fashion, studio portraiture, candids, and even some sports. Use APS-C 45mm for loosely-framed head and shoulders portraits and the wider end for groups and environmental imagery. With this lens's narrow maximum aperture, some of these uses are conditional on sufficient ambient lighting or adequate lighting added, such as flash.

This lens is a perfect choice for recording life and for self-recording. The APS-C 18-45mm focal length range will also be found useful for street photography.

Although APS-C 18mm is not ultra-wide, the 18-55mm range has great utility for photographing landscape and cityscape photography.

It is not difficult to create compelling landscape compositions using the APS-C 18mm perspective while emphasizing a foreground subject against an in-focus background and providing the viewer a sense of presence in the scene. At the other end of the range, APS-C 45mm mildly-compressed landscape images, with a look that is ideal for emphasizing distant subjects, such as mountains.

This focal length range works for commercial photography, and the wide end of the range is ready to capture exterior architecture and larger interior spaces. Countrysides, flowers, medium and large products, and much more are on this lens's capabilities list.

The following images illustrate the APS-C 18-45mm focal length range:

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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 angle of view equivalence multiplier).

Max Aperture

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A lens's maximum aperture is usually included in the product name immediately after the focal length range, reflecting this specification's importance. F/3.5-6.3 is this lens's maximum aperture, the ratio of the focal length to the entrance pupil diameter.

The lower the aperture number, the wider the opening, and the more light the lens can deliver to the imaging sensor. Each "stop" in aperture change (full stop examples: f/2.8, f/4.0, f/5.6) increases or decreases the amount of light by a factor of 2x (a substantial amount).

The additional light provided by wider aperture lenses permits sharp images of subjects in motion and with the camera handheld in lower light levels and 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 narrow aperture's advantages are related to (often significantly) reduced lens element size, including smaller overall size, lighter weight, and lower cost. Right, everyone loves those factors, and those factors were primary in this lens's design.

Want a zoom focal length range in a tiny, lightweight, inexpensive lens? Expect that lens to have a variable max aperture (the aperture opening does not enlarge enough to maintain the same focal length to entrance pupil diameter as the focal length is increased) and for those apertures to be relatively narrow throughout the entire focal length range. That is what we have in the Canon RF-S 18-45mm F4.5-6.3 IS STM Lens.

While the aperture change is continuous, narrowing as the focal length increases, the camera rounds the EXIF reported aperture to the nearest 1/3 or 1/2 stop. Here are the ranges for the reported 1/3 stop apertures.

18-21mm = f/4.5
22-29mm = f/5.0
30-36mm = f/5.6
37-45mm = f/6.3

At 18mm, the f/4.5 aperture is relatively narrow, and the camera is already reporting f/5.0 at 22mm. By 37mm, a slow f/6.3 is reported.

With these narrow max apertures, this lens is not a good choice for photographing low-light motion. Setting the ISO to a high number is the narrow aperture option for sharp low light, in-motion images, and noise is an image quality factor.

A downside to the variable max aperture is that, by definition, the same max aperture cannot be used over the entire focal length selected. The camera automatically accounts for the changes in auto exposure modes (including M mode with Auto ISO), but using the widest-available aperture in manual exposure mode is somewhat complicated by the changing setting (an in-camera function may also accommodate the changes).

When recording video, 1/60 second shutter speeds (twice the framerate) are typically needed (assuming you're not capturing high framerate slow-motion video), and wide apertures are not often required for 1/60 second rates in normally encountered ambient lighting.

An advantage held by wide apertures (and long focal lengths) is their ability to blur the background strongly. This lens does not have those advantages.

The above image shows the maximum blur this lens can create.

Image Stabilization

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When the subject is not moving or not moving much, this lens's image stabilization system, rated for 4 stops of assistance, can make a huge difference in handheld image quality. Use this lens on an EOS R-series camera featuring In-Body Image Stabilization (IBIS), and that rating jumps to a high 6.5 stops. The 4.0 or 6.5 stop ISO noise difference referenced by these ratings is dramatic, offsetting much of the narrow aperture disadvantage (with motionless subjects).

IS is useful for stabilizing the viewfinder, aiding in optimal composition (though this is not as big of an issue with wide-angle focal lengths). IS is also useful for video recording.

The image stabilization system in the RF-S 18-45 performs superbly. IS makes a faint "hmmm" (even when switched off), though it is audible only from about an inch or two from the lens. Canon's IS systems have long been well behaved, referring to the viewfinder image not jumping or fighting strongly against recomposition, including while recording video. I see the image framing drifting only slightly while IS is active and the camera is motionless for a bit.

As mentioned, this highly refined image stabilization system gets a high 4.0 stops of assistance rating and 6.5 stops with coordinated IBIS. Although these are not the highest numbers hitting the streets today, the EF-M 15-45 was rated lower at 3.5 stops. Improved communications between the lens and the camera via the new RF mount accounts for at least some of the improved lens-only rating, and IBIS was not available in the EOS M lineup.

This lens does not have an IS switch. Enabling or disabling IS requires accessing a second-level menu option.

As usual for Canon image-stabilized lenses, the RF-S 18-45mm has an impressively high-performing IS system.

Image Quality

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The old "You get what you pay for" adage usually applies to camera lenses, the RF-S 18-45mm F4.5-6.3 IS STM Lens is the least expensive Canon RF zoom lens available at review time, and the lens is usually the minimum factor for the image quality a camera produces. That set of information sets the stage for the image quality evaluation of this lens.

No one expects a diminutive, ultralight, low-cost to deliver outstanding image quality. Still, none of us prefers to compromise on image quality. Let's find out how the Canon RF-S 18-45mm F4.5-6.3 IS STM Lens optically performs.

With the ultra-high resolution Canon EOS R7 behind it, the RF-S 18-55 produces decent wide-open aperture sharpness in the center of the frame from 18mm through 28mm, and results are noticeably softer at 35mm and 45mm.

In general, lenses are not as sharp at their wide-open apertures as they are when stopped down one or two stops. Often, stopping down only 1/3 of a stop increases sharpness noticeably, but in this case, there is little improvement seen.

Working against the narrower aperture sharpness improvement is the R7's magnification of diffraction effects that begin to show at only f/5.2. So expect, at most, minor sharpness improvement at f/8, and at 18mm, stopping down to f/8 reduces sharpness modestly.

Often, subjects are not placed in the center of a composition. In the periphery of the image circle, where light rays are refracted to a stronger angle than in the center, lenses typically show decreased sharpness. The good news is that this one shows only a slight decline.

We should not expect the RF-S 18-55 to perform like a high-end prime lens. Still, it is interesting to look at such a comparison to understand how a lens performs. Compare other focal lengths for a broader understanding.

The resolution chart is merciless on image quality, so let's take the testing outdoors, next looking at a series of center-of-the-frame 100% resolution crop examples.

These images were captured using an ultra-high resolution Canon EOS R7 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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These results look nice.

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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Samples taken from the outer extreme of the image circle, full-frame corners, can be counted on to show a lens's weakest performance. With that expectation in regard, these results are reasonable.

Does corner sharpness matter? Sometimes it does, sometimes it doesn't. I always prefer my lenses to be razor sharp in the corners in case that feature is needed, but each of us must consider our applications to answer this paragraph's initial question, and if no better option exists, any limitations present must be accepted.

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).

When used on a camera that utilizes a lens's entire image circle, a lens can be expected to create peripheral shading at the widest aperture settings. At 18mm f/4.5, the corners are darkened by about 2.5 stops. Longer focal lengths bring on brighter corners, with just over 1 stop of shading remaining in the 45mm corners. At f/8, about 1 stop of shading is present in the corners, and at f/11, there is just under a stop of shading in the wider focal length corners and just over half a stop in the longer range.

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 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 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.

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 R7 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. Aside from the 45mm result, there is relatively strong color separation apparent in these test images.

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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The wide-angle samples show minor color separation, and the longer focal length samples show modest separation.

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.

On this lens, Canon utilizes Canon SSC (Super Spectra Coating) to reduce flare and ghosting, and the extremely low 7-element count is helpful in this regard. This lens produced practically no flare effects even at narrow apertures in our standard sun in the corner of the frame flare test, showing excellent performance.

Flare effects can be embraced or avoided, or removal can be attempted. Removal is sometimes challenging. Thus, high flare resistance is a welcomed trait of this lens.

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 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). 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 R7 images captured at the widest available aperture.

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Stars in the corner of the frame are seldom rendered as tiny circles, and these show obvious stretching.

To keep your opinion unbiased, an important aspect of this lens's image quality was withheld until this point in the review: this lens has dramatic barrel distortion at the wider end of its focal length range. The geometric distortion is strong enough that Canon forces the correction in the camera and in DPP, regardless of the lens corrections settings. Processing the distortion test images for this lens with third-party software results in the off-the-test-chart framing that shows the true image captured.

At 14mm, there is a lot of extra subject in the uncorrected frame, and the straight line at the top of the test chart is rendered as a strong curve. Though still relatively strong, the 24mm distortion appears considerably reduced and better still at 28mm. The 35mm and 45mm results are nearly free of geometric distortion.

Although today's image correction AI is good, AI does not know what the original subject details were in the stretched areas and calling the result fake detail does not seem untrue.

Does the strong distortion correction matter? Psychologically it does, and an image captured from a non-distorted lens can similarly be up-sized to even higher resolution using the same AI, potentially giving it an advantage. That said, did you notice any corner issues until this point in the review? Let that answer be your guide.

As seen earlier in the review, it is easy to illustrate the strongest blur a lens can create. Due to the infinite number of variables present among all available scenes, assessing the bokeh quality is considerably more challenging. Here are some f/11 (for diaphragm blade interaction) examples.

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The first set of examples shows defocused highlights being relatively smoothly filled in the 18mm and 28mm examples and showing a bright center at the long end. The 45mm example also shows fringing color separation. As expected for a lens with a narrow aperture, the f/11 highlight shapes are nicely rounded.

The second set of examples shows full images reduced in size and, as usual, looking nice.

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.

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

A 7-blade count diaphragm will create 14-point sunstars (diffraction spikes) from point light sources captured with a narrow aperture. In general, the more a lens diaphragm is stopped down, the larger and better-shaped the sunstars tend to be. A narrow max aperture lens does not afford much stopping down before reaching apertures where diffraction causes noticeable softening of details, and this lens does not produce the biggest or best-shaped sunstars.

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The examples above were captured at f/16.

The design of this lens is illustrated above.

The Canon RF-S 18-45mm F4.5-6.3 IS STM Lens was not designed to produce the ultimate image quality. Results from this lens are reasonably sharp, flare effects and color blur are minimal, and lateral CA and distortion amounts are high. However, there are other strong reasons for this lens's existence.

Focusing

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The Canon RF-S 18-45mm F4.5-6.3 IS STM Lens drives AF with a stepping motor.

"Canon's stepping motor (STM) technology is especially effective at producing smooth, quiet autofocus during video recording. This lens is a perfect choice for multi-media content creation, with its zoom range and quiet autofocus. And, STM focus drive provides responsive, quick — and exceptionally quiet — AF during still-image shooting, as well." [Canon]

This lens focuses with good speed, and only light clicks are audible with an ear near the lens in a quiet environment.

While the narrow apertures available on this lens do not create extremely shallow AF system challenging depth of field, accurate focusing remains imperative. This lens provides that.

With DSLR cameras, low light AF from narrow aperture lenses was a challenge. While this lens does not focus in light levels as low as the wider aperture options, EOS R series cameras still lock RF-S 18-45mm lens focus in dark environments (assuming the required contrast is available). Also, despite the long focal length range, this lens's diameter is narrow enough for the LED focus assist lamp to light up a subject in complete darkness.

As usual, low-light AF is slow.

As illustrated in the 100% crops below, the RF 18-45mm lens exhibits near parfocal-like behavior. When focused at 45mm, zooming to wider focal lengths results in minimal focus blur.

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Still, the best practice is to re-establish focus after a focal length change.

This lens provides 100% x 100% of the frame AF coverage for the EOS R7 and R10 and 80% x 80% coverage for the EOS R and EOS R5.

As we've seen in other Canon RF lenses, this lens's control ring serves dual purposes, also acting as a manual focus ring with the Focus/control ring menu option toggling the functionality. From a focus ring perspective, this knurled plastic ring is tiny and positioned immediately in front of the zoom ring. I prefer the forward-positioned focus ring, but the small size indicates that this functionality was not a priority for this lens design. Fortunately, the end of the focus ring is always clear of the lens barrel when extended for use, making the ring accessible from the front and avoiding inadvertent changes to the focal length.

STM 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.

Electronically driven MF enables a variable rate of focus change based on the ring's rotation speed. With the R-series cameras, a linear adjustment speed can be configured, disabling a variable rate when such is available. That option is usually my preference. In this mode, the RF-S 18-45's focus is manually adjusted slowly, with approximately 180° of ring rotation from MFD to infinity, enabling precise manual focusing precision. Switch to the variable adjustment mode for 100° slow (225° at 45mm) or 45° fast full extent rotation.

The manual focus ring has a light resistance, and focus adjustments are smooth and solidly centered with no unusual framing shift.

FTM (Full Time Manual) focusing is supported in AF mode with the camera in One Shot Drive Mode, but the shutter release must be half-pressed for the focus ring to become active (Lens electronic MF after One Shot focusing must be enabled in the menu). With no AF/MF switch provided on the lens, the camera's AF/MF switch (or AF/MF menu option) must be in the "MF" setting and the camera meter must be powered on/awake for conventional manual focusing to be available.

Normal is for the scene to change size in the frame (sometimes significantly) as the focus is pulled from one extent to the other. This 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 strong change in subject size through a full extent focus distance adjustment.

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With a minimum focus distance of 7.9" (200mm), this lens has a high 0.26x maximum magnification spec.

Model	Min Focus Distance "(mm)		Max Magnification
Canon RF-S 10-18mm F4.5-6.3 IS STM Lens	5.5	(140)	0.23x
Canon RF 14-35mm F4 L IS USM Lens	7.9	(200)	0.38x
Canon RF 15-35mm F2.8 L IS USM Lens	11.0	(280)	0.21x
Canon RF 15-30mm F4.5-6.3 IS STM Lens	5.1	(130)	0.52x
Canon EF-M 15-45mm f/3.5-6.3 IS STM Lens	9.8	(250)	0.25x
Canon EF-S 15-85mm f/3.5-5.6 IS USM Lens	13.8	(350)	0.21x
Canon RF-S 18-45mm F4.5-6.3 IS STM Lens	7.9	(200)	0.26x
Canon EF-S 18-55mm f/4-5.6 IS STM Lens	9.8	(250)	0.25x
Canon EF-S 18-135mm f/3.5-5.6 IS USM Lens	15.4	(390)	0.28x
Canon RF-S 18-150mm F3.5-6.3 IS STM Lens	6.7	(170)	0.44x
Canon EF-M 18-150mm f/3.5-6.3 IS STM Lens	9.8	(250)	0.31x
Canon RF 24-105mm F4-7.1 IS STM Lens	5.2	(131)	0.50x
Canon RF 24-240mm F4-6.3 IS USM Lens	19.7	(500)	0.26x

The 0.26x maximum magnification spec is only available via manual focusing — the AF maximum magnification spec ranges from 0.14x at 18mm to 0.16x at 45mm.

At 18mm, a subject measuring approximately 2.8 x 1.9" (71 x 47mm) fills an APS-C imaging sensor at this lens's minimum MF distance. At 45mm, a 2.7 x 1.8" (69 x 46mm) subject does the same.

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The USPS love stamps shared above have an image area that measures 1.05 x 0.77" (26.67 x 19.558mm), and the overall individual stamp size is 1.19 x 0.91" (30.226 x 23.114mm).

At the minimum MF distance, 18mm results are soft, and a strongly curved plane of sharp focus renders corners blurry. The 45mm minimum focus distance performance is better but still not good.

Need a shorter minimum focus distance and higher magnification? An extension tube will significantly 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 otherwise function normally. As of review time, Canon does not offer RF mount-compatible extension tubes, but third-party options are available.

This lens is not compatible with Canon extenders.

Build Quality & Features

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Notable is that the Canon RF-S 18-45mm F4.5-6.3 IS STM Lens features a collapsible design, retracting to a compact, non-functional parked position.

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Powering the camera on with the lens fully retracted results in a "Set the lens to the shooting position" message on the LCD.

A twist of the small zoom ring fully extends the lens 1.07" (27.1mm) from the click-stop-parked position to the 18mm setting. This change is easiest if done firmly and quickly, as the plastic mold-ribbed focus ring lacks traction and the parked click stop is tight. The effort required to retract the lens from 18mm is also firm, making the usable range easy to stay within.

In the useful range, the RF-S 18-45 is shortest at around 30mm

The extended lens barrel has a slight amount of play.

The exterior build is high-quality plastic, including the polycarbonate lens mount.

A knurled plastic control ring, configurable for fast access to camera settings including aperture, ISO, and exposure compensation, shares MF functionality.

As mentioned earlier in the review, this lens does not have an AF/MF switch — or any other switch or button. While omitting switches and buttons simplifies the lens design, I typically want the AF/MF and IS switches.

Canon resolves the first omission by providing an AF/MF switch on, minimally, the first two APS-C imaging sensor format R series cameras, the R7 and R10. Those using this lens on other cameras, such as the EOS RP, must rely on a menu option for this functionality. All must rely on a menu option (second level, nonetheless) to check, enable, or disable image stabilization.

Weather sealing is not a specified feature of this lens, and the mount is not gasketed. Fluorine coatings are omitted.

Get this: of the 523 tested lenses in our measurements and specifications table, only three are lighter than the Canon RF-S 18-45mm F4.5-6.3 IS STM Lens. All three are wide-angle prime (fixed focal length) lenses, and the lightest lens is only 0.5 oz (15g) lighter. Put this little 4.6 oz (130g) lens in your pocket, and you might forget it is there.

Model	Weight oz(g)		Dimensions w/o Hood "(mm)		Filter	Year
Canon RF-S 10-18mm F4.5-6.3 IS STM Lens	5.3	(150)	2.7 x 1.8	(69.0 x 44.9)	49	2023
Canon RF 14-35mm F4 L IS USM Lens	19.1	(540)	3.3 x 3.9	(84.1 x 99.8)	77	2021
Canon RF 15-30mm F4.5-6.3 IS STM Lens	13.8	(390)	3.0 x 3.5	(76.6 x 88.4)	67	2022
Canon RF 15-35mm F2.8 L IS USM Lens	29.7	(840)	3.5 x 5.0	(88.5 x 126.8)	82	2019
Canon EF-M 15-45mm f/3.5-6.3 IS STM Lens	4.6	(130)	2.4 x 1.8	(60.9 x 44.5)	49	2015
Canon EF-S 15-85mm f/3.5-5.6 IS USM Lens	20.3	(575)	3.2 x 3.4	(81.6 x 87.5)	72	2009
Canon RF-S 18-45mm F4.5-6.3 IS STM Lens	4.6	(130)	2.7 x 1.7	(68.9 x 44.3)	49	2022
Canon EF-S 18-55mm f/4-5.6 IS STM Lens	7.6	(215)	2.6 x 2.4	(66.5 x 61.8)	58	2017
Canon EF-S 18-135mm f/3.5-5.6 IS USM Lens	18.2	(515)	3 x 3.8	(77.4 x 96.0)	67	2016
Canon RF-S 18-150mm F3.5-6.3 IS STM Lens	10.9	(310)	2.7 x 3.3	(69.0 x 84.5)	55	2022
Canon EF-M 18-150mm f/3.5-6.3 IS STM Lens	10.6	(300)	2.4 x 3.4	(60.9 x 86.5)	55	2016
Canon RF 24-105mm F4-7.1 IS STM Lens	13.9	(395)	3.0 x 3.5	(76.6 x 88.8)	67	2020
Canon RF 24-240mm F4-6.3 IS USM Lens	26.5	(750)	3.2 x 4.8	(80.4 x 122.5)	72	2019

For many more comparisons, review the complete Canon RF-S 18-45mm F4.5-6.3 IS STM Lensframe imaging sensor models will Specifications using the site's lens specifications tool.

While the RF-S 18-45 spec shows a 2.7" (67mm) diameter, it is only the RF mount that extends to that width. Most of the lens is only 2.45" (62.3mm) wide, and my fingers easily clear the barrel of this lens when tightly gripping the compact EOS R10's grip.

Here is a visual comparison.

Positioned above from left to right are the following lenses:

Canon RF-S 18-45mm F4.5-6.3 IS STM Lens
Canon RF-S 18-150mm F3.5-6.3 IS STM Lens
Canon RF 24-105mm F4-7.1 IS STM Lens
Canon RF 24-240mm F4-6.3 IS USM Lens

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

This lens has 49mm filter threads. While 49mm filters are small and relatively inexpensive, few other lenses use 49mm filters. However, a highly complementary sibling, the Canon RF-S 10-18mm F4.5-6.3 IS STM Lens, has 49mm threads.

A standard thickness circular polarizer filter has little effect on peripheral shading. Still, a slim model such as the Breakthrough Photography X4 is highly recommended.

The Canon EW-53 Lens Hood is not included in the box. While not inexpensive, I recommend getting and using (reversed does not count) the hood for front element protection from impact and flare-inducing bright light.

The plastic EW-53's petal shape is optimized to block as much light outside the utilized image circle as possible. As zoom lens hoods must be tuned for the wide end of the zoom range, less than optimal protection is afforded at the long end. Still, this hood offers reasonable front element protection.

The petal shape also looks cool, and an advantage of this hood shape is easier installation alignment (simply align the small petal to the top), though a round-shaped hood enables the lens to better stand on its hood. The matte interior avoids internal reflections. A release button is not featured on this hood.

The Canon LP814 Lens Case is also optional. Consider a Lowepro Lens Case or Think Tank Photo Lens Case Duo for a quality, affordable single-lens storage, transport, and carry solution.

Price, Value, Compatibility

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While this lens does not produce the ultimate image quality, it makes up for that shortcoming with convenience, utility, and low price. Those factors translate into good value.

Low-cost, good-value lenses frequently become kit lenses. Watch for this lens in a box with the mirrorless interchangeable lens camera you are interested in.

As an "RF-S" lens, the Canon RF-S 18-45mm F4.5-6.3 IS STM Lens is compatible with all Canon EOS R-series cameras. Full-frame imaging sensor models will automatically switch into APS-C mode when an RF-S lens is mounted. Canon USA provides a 1-year limited warranty.

The reviewed Canon RF-S 18-45mm F4.5-6.3 IS STM Lens came in a kit with an EOS R7 on short-term loan from Canon USA.

Alternatives

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The only other Canon RF-S lens at its launch time is the Canon RF-S 18-150mm F3.5-6.3 IS STM Lens.

In the image quality comparison, the two lenses are similarly sharp at 18mm, and the 18-45 has a slight advantage at 35mm. The 18-45 has dramatically more barrel distortion at 18mm and noticeably less pincushion distortion at 35mm and 45mm. With ten fewer lens elements in its design, the 18-45 better resists flare and ghosting, but it has stronger peripheral shading.

The Canon RF-S 18-45mm F4.5-6.3 IS STM Lens vs. Canon RF-S 18-150mm F3.5-6.3 IS STM Lens comparison shows the 18-45 dramatically smaller and lighter than the already small and light 18-150. Also smaller are the 18-55's filter threads, 49mm vs. 55mm. The 18-150 has a higher maximum magnification, 0.44x vs. 0.26x, and a higher IS assistance rating, 4.5 vs. 4.0. The 18-45 is considerably lower priced, but the 18-150 provides a considerably longer focal length range and features wider max apertures at all equivalent focal lengths, a mostly 2/3 stop advantage.

An interesting comparison is against one of the EF-S 18-55mm lens options. There are numerous of these lenses, so I'll pick one of the most recent ones and one that has the most similar maximum wide-angle max aperture, the Canon EF-S 18-55mm f/4-5.6 IS STM Lens.

In the image quality comparison (visualizing between the different camera resolutions), the two lenses perform similarly, with the EF-S lens having a slight advantage at the long end. The EF-S lens has less peripheral shading, shows stronger flare and ghosting effects (12 lens elements vs. 7), has dramatically less barrel distortion at the wide end, and has modestly more pincushion distortion at the long end.

The Canon RF-S 18-45mm F4.5-6.3 IS STM Lens vs. Canon EF-S 18-55mm f/4-5.6 IS STM Lens comparison shows the EF-S small and light, but not nearly as small and light as the RF-S lens. The RF-S lens uses 49mm filters vs. 58mm. The EF-S lens provides ten extra mm of focal length on the long end, has an about 1/3 stop wider aperture at equivalent focal lengths, has AF/MF and IS switches, and costs modestly less. The EF-S lens requires a Canon Mount Adapter EF-EOS R for use on an R series camera, adding modestly to the size, weight, and cost (unless already owned).

The RF-S 18-45mm lens does not share the Canon EF-M 15-45mm f/3.5-6.3 IS STM Lens's design, but these two lenses are similar in size, weight, and purpose within the respective lineup. So, let's compare them.

In the image quality comparison (visualizing between the different camera resolutions), the two lenses appear equally sharp. The EF-M lens has less peripheral shading, dramatically less geometric distortion, and shows more flare effects, in part because it has three additional lens elements.

The Canon RF-S 18-45mm F4.5-6.3 IS STM Lens vs. Canon EF-M 15-45mm f/3.5-6.3 IS STM Lens comparison shows the two lenses weighing and measuring (not considering the larger RF-S mount diameter) the same. The RF-S lens has a higher IS assistance rating, 4.0 vs. 3.5. The EF-M lens's additional 3mm on the wide end are noticeable. The EF-M lens has a release button to permit extension into the usable position and a knurled zoom ring vs. ribbed. The two lenses share the same low price. The EF-M lens mounts only to EOS M series cameras, and the RF-S lens mounts only to EOS R series cameras.

Use the site's tools to create additional comparisons.

Summary

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The primary strengths of the Canon RF-S 18-45mm F4.5-6.3 IS STM Lens were revealed in the first sentence of this review.

This lens is tiny, measuring only 1.7" (44.3mm) in length and mostly 2.5" (62.4mm) in width.

The 4.6 oz (130g) weight is barely noticeable.

While the focal length range is not especially long, it has the most-used focal lengths included.

This lens produces decent image quality and physically performs well. It even has image stabilization that coordinates with IBIS.

Everyone will love that the price tag is lower than any other Canon RF mount zoom lens. Professional photographers will love the low financial risk of treating this lens as disposable in scenarios dangerous to the lens.

While the Canon RF-S 18-45mm F4.5-6.3 IS STM Lens is a fine "Only" lens for a lightweight, low-cost kit, it is also a nice option to have available in a high-end kit.