The 55-210mm F5-7.1 IS STM is Canon's third "RF-S" designated lens, with the "-S" referring to the APS-C imaging sensor-sized image circle it provides.
With the reduced element size required by the APS-C format (vs. full-frame), APS-C lenses tend to be small, light, and affordable. Those attributes are strongly supported by all Canon RF-S lenses to date, including this one.
The inexpensive Canon RF-S 55-210mm IS STM is a nicely constructed little lens with optical image stabilization and decent construction quality. The telephoto zoom focal length range holds great utility, and this simple lens is lots of fun to use. Of course, the memories and art captured by the RF-S 55-210 hold the biggest value.
The focal length range is the first consideration for zoom lens selection. Focal length drives subject distance choices or meets distance-related requirements, and subject distances determine perspective.
The imaging sensors in the APS-C sensor format cameras this lens is designed for are smaller than those in full-frame models. The smaller sensor uses a narrower image circle, framing a scene more tightly. 1.6x is the angle of view equivalence multiplier, and the 55-210mm focal length range provides an angle of view similar to an 88-336mm lens on a full-frame camera.
A short to medium telephoto zoom lens is often the second most used lens in a kit, with only a Canon general-purpose RF lens typically getting more use. With their magnification capability, these lenses enable tighter subject framing or longer working distances for the same framing compared to normal focal length lenses.
What are the uses for a 55-210mm APS-C lens?
Let's start with people, because this lens features a superset of the ideal portrait focal length range (traditionally considered 85-135mm). Before delving into the portrait use discussion, note that this lens's narrow max aperture is a limitation for low-light portrait uses (more about this soon).
Back up and use the wider angles for full-body portraits. With enough working space, this range can even handle small groups. Move closer and use the longer angles for tight headshot portraits.
Engagements, weddings, parties, events, theater, stage performances including concerts and recitals, speakers, kids' events, families, small groups, senior adults, graduating seniors, fashion, documentary, lifestyle ... all are great uses for the 55-210mm focal lengths. There is often adequate space in even a small studio for portraiture with the focal length range provided by this lens. Again, lighting considerations may be a factor for those uses of this lens.
People are also frequently photographed participating in sports are a good target for this focal length range. While the 210mm focal length may be modestly too wide for large-field sports photography, it is ideal for closer action such as that found at track and field meets or on the tennis court.
While it will sometimes be found short for photographing wildlife portraits, the 55-210mm range does have wildlife photography application, especially when the environment is included in the frame or the subjects are large and close. If capturing environmental wildlife portraits or captive (zoo) wildlife, this focal length range may be perfect. This is a great focal length range for photographing pets, including dogs and cats.
When landscape photography is mentioned, many immediately think of wide-angle lenses. However, telephoto focal lengths are an extremely important part of a landscape kit. Telephoto focal lengths can create excellent landscape images, especially when there is a distant subject to be emphasized, rendered large in the frame, such as a mountain. It is so easy to take great telephoto landscape images that it feels (slightly) like cheating.
Use a telephoto lens to focus on closer landscape details, allowing the long focal length to blur the background blur, isolating the details. This focal length range is especially great for capturing clouds, sunsets, and sunrises, allowing the frame to be filled with color from even a modest show in the sky.
Cityscapes are essentially landscape images with cities in them, and this focal length range can be a great choice for more-distant city views. A 55-210mm lens has my most-used studio focal lengths, working especially well for product images and many other general studio applications. Most of the product images on this site were captured within the 88-210mm range and this range is ideal for larger products including vehicles.
Let's head to the swamp to illustrate the 55-210mm focal length range:
This range has many uses, and it nicely complements wide-angle and normal zoom lenses.
How much light does the lens bring to the imaging sensor? Usually, that question is the second most important when selecting a lens.
The F5-7.1 in the name refers to the maximum aperture, the ratio of the focal length to the entrance pupil diameter, available in this lens.
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).
Want a long focal length range that includes telephoto focal lengths in a zoom lens without a large size, heavy weight, and high price? Expect that lens to have a variable and narrow max aperture.
Because this lens's maximum opening does not increase sufficiently with focal length increase to maintain the same aperture measurement ratio, the max aperture is efficiently variable, ranging from f/5 to f/7.1 as the focal length range is increasingly traversed. A smaller aperture opening facilitates using smaller, lighter, and less expensive lens elements. The Canon RF-S 55-210mm F5-7.1 IS STM Lens has all of those attributes.
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 focal length ranges for the Canon RF-S 55-210mm F5-7.1 IS STM Lens's reported 1/3 stop apertures.
55-62mm = f/5
63-84mm = f/5.6
85-142mm = f/6.3
143-210mm = f/7.1
The max aperture steadily reduces to a very dark f/7.1 by only 143mm.
All of these max apertures are very narrow, and this lens is not a good choice for photographing low-light motion, such as indoor sports or outdoor sports on cloudy days. Setting the ISO to a very high number is the narrow aperture option for sharp low light action images, and the resulting significant noise is an image quality factor. Narrow apertures also slow or inhibit low light autofocusing.
Narrow apertures do not afford the strong background blur that wide apertures avail. Still, this lens's short minimum focus distance and telephoto focal lengths can make a strong blur happen.
These examples illustrate the maximum blur this lens can create:
The 55mm background blur capability at 55mm is good, and the background can be strongly blurred at 210mm.
Only a 1/60 second shutter speed (twice the framerate) is needed for 30 fps video capture, and wide apertures are not often required to get 1/60 in normally encountered ambient lighting.
Despite the tiny size, light weight, and low price of the Canon RF 24-50mm F4.5-6.3 IS STM Lens, it features optical image stabilization, a feature especially welcomed on a lens expected to be often used handheld. This feature is also especially welcomed for telephoto focal lengths and narrow apertures.
The RF 55-210's IS system is rated for 4.5 stops of assistance on non-IBIS (In-Body Image Stabilization) cameras and 7 stops of coordinated control assistance on cameras featuring IBIS. While these ratings are not among the highest being produced at review time, 4.5 of assistance is very helpful and the 7-stop rating is outstanding.
This IS implementation is quiet and well-behaved.
An ultra-low price does not set a high bar in terms of image quality expectations. Still, low-cost production quality has increased substantially over the years, and we should keep an open mind going into the Canon RF-S 55-210mm F5-7.1 IS STM Lens review. The enhanced resolution chart lab test usually tells the primary image quality story, and that is where we will start.
In the center of the frame, with a wide-open aperture, this lens delivers reasonable sharpness at 55mm and 70mm. The 100mm results are a touch softer, and the 135mm and 210mm results are a bit soft.
In general, lenses become sharper as they are stopped down one or two stops from their wide-open apertures. However, the Canon EOS R7 has a diffraction-limited aperture of about f/5.2. Thus, the effects of diffraction decrease sharpness as the aperture narrows beyond this opening, and this lens shows little sharpness improvement at f/8 at 55mm through 100mm. At 135mm and 210mm, f/8 brings sharpness up to that of the wider focal lengths.
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.
This lens's center sharpness description holds well into the periphery of the image circle. Stopping down primarily decreases peripheral shading.
Let's pause here for a reality check. The Canon RF-S 55-210mm F5-7.1 IS STM is an inexpensive lens and should not be expected to perform like a high-end professional lens. However, an educated buyer should understand the difference.
The resolution chart is brutal/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.
These results appear 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.
Samples taken from the outer extreme of the image circle, full-frame corners, can be counted on to show a lens's weakest performance. Primarily, the 210mm results show that degradation here.
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).
A lens is expected to show peripheral shading at the widest aperture settings when used on a camera that utilizes its entire image circle. At 55mm, the corners have a modest amount of shading — just under 2 stops. The shading diminishes by 70mm, with under 1.5 stops remaining. Then, the amount increases to just under 2 stops by 135mm through 210mm.
Stopping down the aperture reduces shading. At f/8, the 55mm shading drops to just over 0.5 stops. F/8 is less stopped down at the longer focal lengths, and just under 1.5 stops of shading remains in 210mm f/8 corners. F/11 brings the 210mm shading down to just under 1 stop.
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.
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 EOS R7 frames showing diagonal black and white lines.
Only black and white colors should be present in these images, with the additional colors indicating the presence of lateral CA. The color separation is modest at the wide end, slowly decreases to negligible at 70mm, and increases to moderate by 135mm through 210mm.
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.
Narrow aperture lenses typically produce little color separation in this test, and this lens is typical in that regard.
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.
Canon utilizes Super Spectra Coating to combat flare and ghosting, and the low 11-element count is helpful in this regard (fewer light-reflecting surfaces). This lens produced practically no flare effects even at wide-open apertures in our standard sun in the corner-of-the-frame flare test. However, moderately strong streaking affected the f/16 results.
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 R7 images captured at the widest available aperture.
For the price of this lens, those results are not bad.
This lens has pincushion distortion at 55mm, and moderate pincushion distortion at the rest of the marked focal lengths.
Most modern lenses have correction profiles available (including in-camera), and distortion can easily be removed using these. Still, distortion correction is destructive at the pixel level as some portion of the image must be stretched or the overall dimensions reduced.
As seen earlier in the review, it is easy to illustrate the strongest blur a lens can create, and telephoto lenses are inherently advantaged in this regard. Due to the infinite number of variables present among available scenes, assessing the bokeh quality is considerably more challenging. Here are some f/11 (for diaphragm blade interaction) examples.
The first set of examples shows 100% crop samples of defocused highlights appearing normal and filled rather smoothly. The blades are not stopped down much to create f/11, and as expected from a lens with narrow max apertures, the f/11 highlight shapes are nicely rounded.
The second set of examples shows full images reduced in size and looking very 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.
The truncation effects this lens produces increase in strength as the focal length increases, with very strong truncation at 210mm. As the aperture narrows, the entrance pupil size is reduced, and the mechanical vignetting diminishes, making the corner shapes rounder. However, this lens does not afford much stopping down.
A 7-blade count diaphragm will create 14-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. Unfortunately, as just mentioned, a narrow max aperture lens does not afford much stopping down before reaching apertures where diffraction causes noticeable softening of details, and these lenses typically do not produce the biggest or best shaped sunstars.
The f/16 examples above appear weak as expected. If strong diffraction spikes are your goal, this is not the optimal lens choice.
The design of this lens is illustrated above.
The Canon RF-S 55-210mm F5-7.1 IS STM Lens produces good image quality for its price.
Accurate focus is critical for most images, and we usually rely on autofocus for that task. Driven by a leadscrew-type stepping motor (referenced by the "STM" in the moniker), the Canon RF-S 55-210mm F5-7.1 IS STM Lens autofocuses accurately and fast (unless a vast focus distance change is required). The focus is internal and quiet, with only a light hum and faint clicks heard.
Generally, wide-aperture lenses enable AF systems to perform their best in low-light environments, and this lens is not the low-light AF king. Still, it is impressive to see the latest camera models lock this lens's focus on adequate contrast in a very dark environment. As usual, AF is slow in low light.
Canon's STM AF systems' smooth focusing is a highly desired trait for movie recording.
Non-cinema lenses usually require refocusing after a focal length change. As illustrated in the 100% crops below, the reviewed lens does not exhibit perfect parfocal characteristics, but it performs relatively well in this regard.
When focused at 210mm, zooming to wider focal lengths results in a slight focus blur at 135mm, with the wider focal lengths covering the subject in their wide-open apertures' depth of field.
To be safe, re-establish focus when you adjust the focal length. This rule usually applies.
Many of these examples provide another look at the wide-open image quality this lens produces.
The RF 55-210 STM's control ring serves dual purposes, acting as a manual focus ring when that functionality is selected in camera (I prefer a switch on the lens).
From a focus ring perspective, this tactilely distinct knurled plastic ring is compact and positioned in front of the non-extending portion of the lens, where it is easy to find. The rotational resistance is light but sufficient.
Unless a linear focus adjustment rate is selected in the EOS camera menu, this lens provides a variable rate of focus adjustment based on the rotational speed of the focus change. At 55mm, a full-extent focus distance change requires a 360° slow rotation or a 90° fast rotation. At 210mm, about 220° and 1,675° (nearly 5 full rotations) are the approximate experienced angles. A fast turn of the ring provides significant focus distance adjustments quickly, while a slow turn facilitates precise adjustments.
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, and anyone critically framing while adjusting focus.
This lens produces a modest to moderate change in subject size through a full-extent focus distance adjustment.
The RF-S 55-210mm IS STM Lens has a minimum focus distance of 28.7" (700mm) for a quite respective 0.28x maximum magnification spec. Interesting is that this lens has a longer minimum focus distance at the wide end, with 39.4" (1000mm) the 55mm spec. Combined with the reduced focal length magnification, the maximum magnification at 55mm is only 0.05x.
|Canon RF-S 18-150mm F3.5-6.3 IS STM Lens||6.7"||(170mm)||0.44x|
|Canon EF-M 55-200mm f/4.5-6.3 IS STM Lens||39.4"||(1000mm)||0.21x|
|Canon RF-S 55-210mm F5-7.1 IS STM Lens||39.4"||(700mm)||0.28x|
|Canon EF-S 55-250mm f/4-5.6 IS STM Lens||33.5"||(850mm)||0.31x|
|Canon RF 70-200mm F4 L IS USM Lens||23.6"||(600mm)||0.28x|
At 55mm, a subject measuring approximately 14.9 x 10.0" (379 × 254mm) fills the imaging sensor at this lens's minimum MF distance. Zoom to 210mm, and a 3.1 x 2.1" (78 × 53mm) subject does the same.
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). While this lens produces sharp center of the frame details at the 210mm minimum focus distance, expect the image periphery to be soft due to field curvature.
Need a shorter minimum focus distance and higher magnification? Mount an extension tube behind this lens to moderately decrease and increase those respective numbers at the wide end, and modestly do so at the long end. 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.
This lens is not compatible with Canon extenders.
All of Canon's RF-S consumer zoom lenses seem nicely constructed with tight tolerances, and the Canon RF-S 55-210mm F5-7.1 IS STM Lens is no exception.
This is a simple lens, featuring a quality plastic external construction and smooth external dimensions that make it comfortable to hold and easy to use.
The large 1.82" (46.2mm) ribbed plastic zoom ring is easy to find, slightly slippery from a grip perspective, and smooth in function. This lens extends 1.62" (41.1mm) when zoomed to 210mm. When fully extended, the inner lens barrel has remarkably little play for a lens at this price point.
The knurled Control Ring, when selected instead of MF in the camera menu system, can be configured for fast access to settings that include aperture, ISO, and exposure compensation. Both functions cannot be used simultaneously, but sharing functionality means there is one less ring to confuse. Note that this control ring turns smoothly — it is not clicked.
This lens has no switches or buttons, and a camera menu option is required to enable or disable IS. The simplified interface will be welcomed by casual photographers.
This lens is not weather sealed, and the front and rear elements are not fluorine-coated to repel dust and water drops and facilitate cleaning.
At 2.7 x 3.7" (68.6 x 94") in size and 9.5 oz (270g) in weight, this lens is exceptionally compact and lightweight. Ignore the mount diameter, and this lens's width measures only 2.44" (61.9mm).
|Model||Weight oz(g)||Dimensions w/o Hood "(mm)||Filter||Year|
|Canon RF-S 18-150mm F3.5-6.3 IS STM Lens||10.9||(310)||2.7 x 3.3||(69 x 84.5)||55||2022|
|Canon EF-M 55-200mm f/4.5-6.3 IS STM Lens||9.2||(260)||2.4 x 3.4||(60.9 x 86.5)||52||2014|
|Canon RF-S 55-210mm F5-7.1 IS STM Lens||9.5||(270)||2.7 x 3.7||(68.6 x 94)||55||2023|
|Canon EF-S 55-250mm f/4-5.6 IS STM Lens||13.2||(375)||2.8 x 4.4||(70 x 111.2)||58||2013|
|Canon RF 70-200mm F4 L IS USM Lens||24.5||(695)||3.3 x 4.7||(83.5 x 119)||77||2020|
For many more comparisons, review the complete Canon RF-S 55-210mm F5-7.1 IS STM Lens Specifications using the site's lens specifications tool.
Here is a visual comparison:
Positioned above from left to right are the following lenses:
Notice how closely the RF-S 55-210 resembles the Canon RF-S 18-150mm F3.5-6.3 IS STM Lens. 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-S 55-210mm F5-7.1 IS STM Lens to other lenses.
This lens's filter thread size matches its widest angle, 55mm. 55mm filters are small and affordable, but lenses using this size are not abundant.
Canon still does not ship lens hoods with consumer-grade lenses, making the Canon RF-S 55-210mm F5-7.1 IS STM Lens's ET-60B hood an optional accessory. The ET-60B is a modest-sized, round-shaped, semi-flexible, bayonet-mount (no release button), plastic hood, with a matte interior finish. This hood provides significant protection from impact and bright, flare-inducing light.
Also excluded from the lens box is a case. This lens requires only a small case, and Canon suggests their Lens Case LP1016, a drawstring pouch that adds dust and minor impact protection (the bottom is well-padded).
These nice lens caps are included.
At review time, only four RF-mount Canon lenses are less expensive than this one. The RF 55-210's utility-to-price ratio is very high.
As an "RF-S" lens, the Canon RF-S 55-210mm F5-7.1 IS STM Lens is compatible with all Canon EOS R-series cameras, including full-frame and APS-C models. Full-frame cameras will automatically crop the angle of view to the covered APS-C image circle. Canon USA provides a 1-year limited warranty.
The reviewed Canon RF-S 55-210mm F5-7.1 IS STM Lens was online-retail sourced.
At review time, the RF lens with the most similar focal length range is the RF 70-200mm F4 L IS USM. This professional-grade full-frame lens far outclasses the RF-S 55-210, including with the price. Still, it is interesting to look at the differences.
The image quality comparison requires visualization between the different cameras used, but the RF 70-200 is considerably sharper with a wide-open aperture that is one to almost two stops wider than the RF-S 55-210 has available. At f/4 on a full-frame body, the RF 70-200 has similar or less peripheral shading than the RF-S lens wide-open except at 210mm where the RF-S lens has a wide-open advantage. At the RF-S lens's maximum apertures and used on an APS-C camera, the RF lens is greatly advantaged in this regard. The RF 70-200 has less geometric distortion even when used on a full-frame camera.
The Canon RF-S 55-210mm F5-7.1 IS STM Lens vs. RF 70-200mm F4 L IS USM Lens comparison shows the RF-S lens is considerably lighter and much smaller. The smaller lens uses smaller filters, 55mm vs. 77mm. The 70-200 L lens has two additional aperture blades, 9 vs. 7, a 5-stop-rated IS system vs. 4.5, and features Dual Nano USM AF vs. STM and a full array of switches, including a focus limit switch. The price comparison between these two lenses somewhat mirrors the weight comparison, but the L lens does come with a hood.
The most review-time comparable RF-mount lens is the Canon RF-S 18-150mm F3.5-6.3 IS STM. This lens shifts the focal length range significantly wider, and it is a stretch to call these lenses comparable, but the two resemble each other and have enough overlap to create a comparison.
In the image quality comparison, the 55-210 is a bit sharper at 70mm, and the 18-150 is a bit sharper in the center at 135/150mm. The 18-150 has less geometric distortion at 135/150mm
The Canon RF-S 55-210mm F5-7.1 IS STM Lens vs. RF-S 18-150mm F3.5-6.3 IS STM Lens comparison shows the two lenses as similar as they look. The 18-150 has a 0.44x maximum magnification vs. 0.28x, and the 55-210 reports a 1/3-stop-wider aperture over a short portion of the shared focal length range. While itself inexpensive, the RF-S 18-150mm lens is moderately more expensive than the RF-S 55-210mm lens.
If willing to use an adapter, the Canon EF-S 55-250mm f/4-5.6 IS STM Lens becomes an option worth comparing.
In the image quality comparison, The RF-S lens is slightly sharper at 55mm, the EF-S lens is slightly sharper in the center at 70mm and noticeably sharper overall at the longer focal lengths. The EF-S lens has less geometric distortion and less peripheral shading even at its wider max apertures.
The Canon RF-S 55-210mm F5-7.1 IS STM Lens vs. EF-S 55-250mm f/4-5.6 IS STM Lens comparison shows the EF-S lens weighing 3.7 oz (105g) heavier and measuring modestly longer. While the diameter is not greatly different, the EF-S lens consumes a considerably larger volume. Adding the R-series required Mount Adapter EF-EOS R about doubles the length and weight differences. The EF-S lens has about 2/3 stop max aperture advantage at comparable focal lengths and has a longer focal length range that provides an extra 40mm on the long end. The RF-S lens has a 4.5-stop-rated IS system vs. 3.5. The EF-S lens is moderately less expensive if the adapter cost is not factored in. Otherwise, the reverse is true.
Use the site's tools to create additional comparisons.
As likely already made clear, the Canon RF-S 55-210mm F5-7.1 IS STM Lens is a compact, ultra-lightweight, and highly inexpensive telephoto zoom lens. Despite those features, this lens has optical image stabilization, reasonable build quality, and a good AF system.
Of utmost importance is that this lens's focal length range is extremely useful, especially for families.
While it doesn't deliver the ultimate image quality, the entry-level Canon RF-S 55-210mm F5-7.1 IS STM Lens is a good choice for travel, for kids, for long carrying periods, and for any other time the primary features of this lens are required or desired.
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