Canon 20-50mm f/4L IS USM PZ
Optically-Stabilized Power Zoom
Sample Images Intro New Good Bad Missing
Specifications Performance User's Guide
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R7 R10 R50 R50V R100 Bodies Compared
Canon RF 20-50mm f/4L IS USM PZ (67mm filters, 14.695 oz./416.7 g, 0.8'/0.24m close focus, 0.33× macro ratio, $1,399). bigger.
I got mine at B&H. I'd also get it at Amazon, at Crutchfield or at Adorama, or get it used at eBay (How to Win at eBay), or get it used at KEH.
My junk-free, all-content website's biggest source of support is when you use those or any of these links to the places I use myself when you get anything, and it costs nothing more. I've bought from these places for over 100 combined years because they have the best service, the best selection, the best prices, and usually 100% cash-back returns for at least 30 days if you don't love your new goodies. As an Amazon Associate and eBay Partner Network Affiliate, I earn from qualifying purchases. Thanks! Ken.
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Sample Images top
Sample Images Intro New Good Bad Missing
Specifications Performance User's Guide
More samples throughout this review at Bokeh, Falloff, Macro, Spherochromatism and Sunstars.
These are just snapshots; my real work is in my Gallery.
These are all shot hand-held as LARGE NORMAL (
Lifeguard Tower, 6:18 PM, Wednesday, 02 September 2026. Canon R6 V with RF 20-50mm f/4L IS USM PZ at 20mm at f/10 at 1/400 at Auto ISO 100 (LV 15¼), Radiant Photo software to add light. bigger or camera-original 32 MP © 8.2 MB JPG file.
Sea Stone, 6:59 PM, Wednesday, 02 September 2026. Canon R6 V with RF 20-50mm f/4L IS USM PZ at 20mm at f/11 at 1/125 at Auto ISO 100, -0.7 stops exposure compensation (LV 11.6), as shot. bigger or camera-original 32 MP © 11.5 MB JPG file.
Since the R6 V has no finder and we're always having to use the rear screen, it encourages shooting from odd angles. This shot is from about a foot (30 cm) off the sand, making a small stone mound look huge.
Sunset, Solana Beach, 7:12 PM, Monday, 07 September 2026. Canon R6 V with RF 20-50mm f/4L IS USM PZ at 41mm at f/4.5 at 1/80 at Auto ISO 100, -0.7 stops exposure compensation (LV 10¾), Radiant Photo software to add light. bigger.
2018 Hand-Finished Porsche Exclusive Manufaktur 911 Turbo S (Sonderwunsch of 500) in Golden Yellow Metallic, 10:04 AM, Saturday, 29 August 2026. Canon R6 V with RF 20-50mm f/4L IS USM PZ at 31mm at f/5 at 1/100 at Auto ISO 100, -0.3 stops exposure compensation (LV 11¼), Radiant Photo software to add light. bigger or camera-original 32 MP © 6.6 MB JPG file.
1988 Porsche 911 in Guards Red, 9:22 AM, Saturday, 29 August 2026. Canon R6 V in square-crop mode with RF 20-50mm f/4L IS USM PZ at 36mm wide-open at f/4 hand-held at 1/25 at Auto ISO 100, -0.7 stops exposure compensation (LV 11¼), Radiant Photo software to add light. bigger or camera-original 32 MP © 8.9 MB JPG file.
Palm Beach, 6:36 PM, Thursday, 03 September 2026. Canon R6 V, RF 20-50mm f/4L IS USM PZ at 50mm at f/7.1 at 1/200 at Auto ISO 100, (LV 13¼), Radiant Photo software to add light. bigger or camera-original 32 MP © 7.3 MB JPG file.
Introduction top
Sample Images Intro New Good Bad Missing
Specifications Performance User's Guide
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I buy only from these approved sources. I can't vouch for ads below. |
The RF 20-50mm f/4L IS USM PZ is is a compact, inexpensive lens with superb optics and stabilization.
It's a Power Zoom lens, meaning that it zooms by way of a tiny internal motor. The zoom ring is a digital encoder which tells the motors how to set the lens. The zoom ring has no mechanical connection to anything.
You can turn the zoom ring and the motor will zoom the lens to the focal length you've set like a conventional lens, or instead turn the zoom ring between "W—T" to tell the lens to motor in or out with variable speeds for smooth video.
Both the R6V and R50V have an extra "W—T" lever around their shutter buttons so you can zoom it with your shutter finger. More at User's Guide. Any of the "W—T" controls have variable speeds.
The power zoom works great, letting us zoom with the gentle touch of a fingertip. It will have a slight delay if you flick the ring quickly, but it doesn't get in the way.
It's a great zoom range for nature, landscape, stills, B-roll and establishing shots, but a weird choice as a main lens for dialog and dramatic video productions.
I got my RF 20-50mm PZ at B&H. I'd also get it at Amazon, at Crutchfield or at Adorama, or get it used at eBay (How to Win at eBay), or get it used at KEH.
New intro top
Canon's first Power Zoom (PZ) for full-frame mirrorless. Its only other PZ is the RF-S 14-30mm IS STM PZ for APS-C.
Canon's first ultrawide-to-normal mirrorless zoom, reminiscent of the stunning EF 17-40mm f/4L USM. The only similar camera-brand mirrorless lens is Sony's unstabilized FE 20-70mm f/4 G from 2024.
Good intro top
Ultrafast autofocus; I can't recall any lens autofocusing faster.
Ultra sharp.
Superb image stabilization.
Easy zooming with a fingertip!
Great Sunstars.
Programmable Fn button, it's a Focus Lock button by default.
AF/MF switch.
Stabilizer switch.
Made in Japan.
100% U.S.A.-based high-quality technical support at (800) OK-CANON.
Bad intro top
Nothing, if you find this a useful zoom range.
Missing intro top
Mounting index dot not raised so it can't be found by feel in the dark.
No aperture ring.
No focus or depth-of-field scales.
No infra-red focus indices.
Will not work with any teleconverters.
RF 20-50mm f/4L IS USM PZ on a Canon EOS R6 V. bigger.
Specifications top
Sample Images Intro New Good Bad Missing
Specifications Performance User's Guide
I got my RF 20-50mm PZ at B&H. I'd also get it at Amazon, at Crutchfield or at Adorama, or get it used at eBay (How to Win at eBay), or get it used at KEH.
Compatibility & Format specifications top
This lens only works on Canon's EOS-R series of mirrorless cameras.
It won't work with any teleconverters.
It won't fit on, and cannot be adapted to, any DSLR because a DSLR has too much distance between its sensor and its lens mount flange.
This is a full frame lens and I'm reviewing it as such.
While it works fine on APS-C cameras, you're paying a premium price for the privilege of covering full frame. Using it on an APS-C camera throws away more than half of the image from this lens. For use on APS-C, the very inexpensive RF-s 18-45mm IS STM does mostly the same thing for a quarter of the of the price, and the Tamron 17-70mm f/2.8 does even more for a half of the price.
Name specifications top
Canon calls this the Canon RF 20-50mm f/4 L IS USM PZ:
RF: Works only on Canon's EOS-R Mirrorless cameras.
L: Expensive as L.
IS: Image Stabilization.
USM: UltraSonic (focus) Motor.
PZ: Power zoom with an internal motor.
Optics specifications top
Canon RF 20-50mm f/4 L IS USM PZ. Regular Optical Glass, UD glass and Aspherical elements. Red box shows the Image Stabilizer section. Dashes show the Air-Sphere coating.
13 elements in 11 groups.
3 UD Glass extra-low dispersion elements, which help reduce secondary axial chromatic aberration.
2 Aspherical elements.
Fluorine front coating to resist crud.
Super Spectra multicoating, also has an Air Sphere variable-refractive index coating (ASC) on the inside of the front element.
Internal motorized zoom. Nothing moves externally.
Diaphragm specifications top
Canon RF 20-50mm f/4L IS USM PZ. bigger.
9 rounded blades.
Electronically actuated.
Stops down to f/22.
Filters specifications top
Plastic 67mm filter thread.
Focal Length specifications top
20-50mm.
When used on Canon's APS-C cameras, it sees the same angle of view as a 32 ~ 80mm lens sees when used on a full-frame or 35mm camera.
See also Crop Factor.
Angles of View, Full-Frame specifications top
94º ～ 46º diagonal.84º ～ 40º horizontal.
62º ～ 27º vertical.
Focus specifications top
No external movement as focussed, so no air or dust is sucked in.
One nano USM focus motor.
Focus Scale specifications top
No.
Not on lens, but may be displayed in-camera.
Infinity Focus Stop specifications top
No.
You have to focus somehow to get precise focus at infinity, just like at every other distance.
Zooming specifications top
Power zoom only with two nano USMs; no direct mechanical control.
Zooms either by setting a precise focal length on the zoom ring, or with a "W—T" setting.
Depth of Field Scale specifications top
No.
Not on lens, but may be displayed in-camera.
Infrared Focus Index specifications top
No.
Close Focus (distance from subject to image plane) specifications top
0.8 feet (9.5 inches or 0.24 meters).
Maximum Reproduction Ratio specifications top
1:3 (0.33×) at 50mm.
1:7.1 (0.14×) at 20mm.
Image Stabilizer specifications top
Rated 6 stops improvement on any camera, and 8 stops on any internally-stabilized camera!
Caps specifications top
Canon E-67II 67mm front cap, included.
RF II Rear Lens Cap (p/n 7464C001), or the older RF Rear Lens Cap (p/n 2962C001) included, depending on when your 20-50mm was made.
Hood specifications top
The EW-73H Hood is included:
Case specifications top
Nice LP1219 pseudosuede sack included:
Canon LP1219 Lens Sack. bigger.
Size specifications top
3.146" ø maximum diameter × 3.874" extension from flange.
79.9 mm ø maximum diameter × 98.4 mm extension from flange.
Weight specifications top
14.695 oz. (416.7 g), actual measured weight.
Rated 14.81 oz. (420 g).
Quality specifications top
Made in Japan.
Environment specifications top
Rated to work down to xxº C (xxº F).
Announced specifications top
13 May 2026.
Promised for specifications top
Late June 2026.
Included specifications top
Lens.
E-67II 67mm front cap.
RF II Rear Lens Cap (p/n 7464C001), or the older RF Rear Lens Cap (p/n 2962C001), depending on when your 20-50mm was made.
Packaging specifications top
Microcorrugated cardboard box:
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Box. bigger. |
Box end. bigger. |
Corrugami internal supports.
Model Numbers specifications top
Model number: RF20-5040LISPZ.
Product code: 7286C002 (7286C001 in Japan).
JAN code: 4549292-251227.
Price, U. S. A. specifications top
May 2026 (Introduction) ~ September 2026
$1,399 at B&H, at Amazon, at Crutchfield and at Adorama.
213,400 ¥ in Japan.
Performance top
Sample Images Intro New Good Bad Missing
Specifications Performance User's Guide
I got my RF 20-50mm PZ at B&H. I'd also get it at Amazon, at Crutchfield or at Adorama, or get it used at eBay (How to Win at eBay), or get it used at KEH.
Overall Autofocus Manual Focus Breathing
Distance Recording Bokeh Distortion Ergonomics
Falloff Filters Flare & Ghosts Lateral Color Fringes
Lens Corrections Macro Mechanics Sharpness
Spherochromatism Stabilization Sunstars
Teleconverters Weather Sealing
Overall performance top
This is an ultrasharp, lightweight and great-handling lens.
If you need the 20-50mm focal length, this is a great choice.
Autofocus performance top
Autofocus is nearly instantaneous, even at the 50mm end and having to go from infinity to close-up, and it's just about silent.
I can't recall ever using a lens with faster autofocus.
Manual Focus performance top
Manual focusing is entirely electronic; the manual focus ring isn't connected to anything other than a digital encoder.
Focus Breathing performance top
Focus breathing is the image changing size (growing and shrinking slightly) as focused in and out. It's important to cinematographers that the image not breathe (change size) as focus gets pulled back and forth between different actors as they speak. The image is said to breathe because it expands and contracts as the focus follows the dialog back and forth.
The image from this lens shrinks slightly as focused more closely at 20mm and shrinks more at 50mm, while in most of the range there is no breathing. It's as if the system is using the power zoom system to compensate this optically, but it has to give up at the ends of the zoom range.
But seriously, this is an awfully short lens for shooting dialog between two people.
Focus Distance Recording performance top
The focused distance is recorded in the EXIF data.
I read this in the lower left of my screen in Photoshop's lens correction filter.
Bokeh performance top
Bokeh, the feel, character or quality of out-of-focus areas as opposed to how far out of focus they are, is swell. Nothing ever gets that far out of focus with a lens this slow and wide, and when it does, it's smooth at large apertures, but rough at small apertures.
Here are photos from headshot distance wide-open. I'm focused on the DAVIS logo. Click either for the © camera-original file:
Made-in-U. S. A. Davis 6357 Vantage Vue Wireless Sensor Suite (use with WeatherLink console), Monday, 31 August 2026. Canon R6 V, RF 20-50mm f/4L IS USM PZ at 1/2,500 at Auto ISO 100 (LV 15.4).
Click either for the © camera-original file.
As always, if you want to throw the background as far out of focus as possible, shoot 50mm at f/4 and get as close as possible.
Distortion performance top
This lens uses electronic distortion correction as an integral part of its optical design. Therefore this correction cannot be turned off.
If you shoot raw data rather than JPG images, whatever software you use to create visible images from raw data may or may not correct the distortion as is done in-camera as JPGs. You're on your own there; I don't bother with raw data
While Canon's own software probably also corrects this from RAW CR3 files, be warned that other brands of raw processing software probably won't correct the distortion, and Heaven only knows what distortion you may see then.
For more critical scientific use, use these corrections in Photoshop's lens correction filter to JPG images.
These aren't facts or specifications, they are the results of my research that requires hours of photography and calculations on the resulting data.
On Full-Frame at 30' (10m) |
Correction factor to use with images made with correction ON in R6 V |
20mm |
+1.25 |
24mm |
+0.20 |
28mm |
+1.50 |
35mm |
+0.40 |
50mm |
+0.20 |
© 2026 KenRockwell.com. All rights reserved.
Ergonomics performance top
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Canon RF 20-50mm f/4L IS USM PZ. bigger. |
Canon RF 20-50mm f/4L IS USM PZ. bigger. |
The front programmable ring always has clicks, and what it does can be programmed in your camera. It is strongly damped, probably to keep us from turning it accidentally when reaching for the zoom ring.
The middle programmable ring, usually set to manual focus by default, is entirely electronic. It also is strongly damped, probably to keep us from turning it accidentally when reaching for the zoom ring.
There may not be an always-responsive instant manual-focus override unless you enable this in a menu. Manual focus override never works in SERVO AF; while the lens will focus manually as you turn the ring, as soon as you stop the AF system takes over again.
Zooming works extremely well. Set to the 20~50mm portion of the ring, it zooms with only the gentlest brush of a fingertip, perfect!
Set to W—T, it zooms in or out slowly or quickly depending on how far you turn the ring towards T or W. More at Usage.
Falloff performance top
Falloff is invisible at every setting with Peripheral Illumination Correction left at its default of ON.
I've greatly exaggerated the falloff by shooting a gray field and placing these on a gray background; it will not look this bad in actual photos of real things:
f/4 |
f/5.6 |
f/8 |
|
20mm |
 |
 |
|
31.6mm |
 |
 |
 |
50mm |
 |
 |
 |
If you save only raw data rather than create JPG images in-camera, whatever software you use to create visible images from that raw data later may or may not correct this as is done in-camera as JPGs. You're on your own there; I don't bother with raw data.
If you go out of your way to turn off the correction, or possibly in some raw software, this is what you get, which is also invisible in actual shooting at other than f/4:
f/4 |
f/5.6 |
f/8 |
|
20mm |
 |
 |
 |
31.6mm |
 |
 |
 |
50mm |
 |
 |
 |
Filters, use with performance top
There's no need for ultra-thin filters, but I can only use one regular 67mm filter before I start to get vignetting at 20mm on full-frame.
Avoid polarizers at the 20mm end; the sky's natural polarization can appear as a dark band across the sky.
Flare & Ghosts performance top
Flare and ghosts are about as well controlled as most other modern lenses.
See examples at Sunstars.
Nice is that I see a couple of flare-stopping rings inside the lens.
Lateral Color Fringes performance top
There are no lateral color fringes when shot as JPG with the default Chromatic Aberration Correction left ON.
if you go out of your way to turn this OFF (or shoot raw and then use non-manufacturer software to process that data into images) then there is just the tiniest bit of green/magenta fringing at all focal lengths.
This is excellent performance.
Lens Corrections performance top
Other cameras may vary as the years roll on, but my EOS R1, R3, R5 II, R5, R6 III, R6 II, R6, R6V, R, R8 II, R8, RP, R7, R10, R50, R50V and R100 all have options to correct for falloff (Peripheral Illumination Correction), Distortion and a Digital Lens Optimizer which corrects for a suite of other aberrations.
These are all ON by default. You can turn off falloff (peripheral) correction and/or the Digital Lens Optimizer.
If you turn off the Digital Lens Optimizer, you are then offered à la carte ON/OFF options for Chromatic Aberration Correction and Diffraction Correction.
This lens integrates electronic distortion correction as part of its optical design so the Distortion setting is grayed-out because it cannot be turned off.
If you shoot raw data rather than JPG images, whatever software you use to create visible images from raw data may or may not correct these as is done in-camera as JPGs. You're on your own there; I don't bother with raw data.
Macro Performance performance top
Macro gets very close, but suffers from low contrast from spherical aberration at f/4, so stop it down for best results — and to get enough depth of field to get anything in focus.
Stopped down, it is dangerously sharp, so sharp in fact that I had to skip my usual resharpening of both cropped images shown below!
Wide Open at f/4
Casio G-Shock Solar Atomic Watch at close-focus distance, Monday, 31 August 2026. Canon R6 V, RF 20-50mm f/4L IS USM PZ at 50mm at f/4 at 1/2,000 at Auto ISO 100, (LV 15.0). bigger or camera-original 32 MP © 4.3 MB JPG file.
1,200 × 900 pixel (5.8× magnification) unsharpened crop from above. bigger or camera-original 32 MP © 4.3 MB JPG file.
See the halos around the white letters? That's spherical aberration, and it goes away as stopped down as you'll see next at f/8.
If this 1,200 × 900 pixel crop is about 3" (8cm) wide on your screen, then the complete image printed at this same extreme magnification would be about 12 × 18" (30 × 45 cm).
If this 1,200 × 900 pixel crop is about 6" (15cm) wide on your screen, then the complete image printed at this same extreme magnification would be about 23 × 35" (59 × 89 cm).
If this 1,200 × 900 pixel crop is about 12" (30cm) wide on your screen, then the complete image printed at this same extreme magnification would be about 47 × 70" (119 × 178 cm).
At f/8
Casio G-Shock Solar Atomic Watch at close-focus distance, Monday, 31 August 2026. Canon R6 V, RF 20-50mm f/4L IS USM PZ at 50mm at f/8 at 1/500 at Auto ISO 100, (LV 15.0). bigger or camera-original 32 MP © 5.2 MB JPG file.
1,200 × 900 pixel (5.8× magnification) unsharpened crop from above. bigger or camera-original 32 MP © 5.2 MB JPG file.
If this 1,200 × 900 pixel crop is about 3" (8cm) wide on your screen, then the complete image printed at this same extreme magnification would be about 12 × 18" (30 × 45 cm).
If this 1,200 × 900 pixel crop is about 6" (15cm) wide on your screen, then the complete image printed at this same extreme magnification would be about 23 × 35" (59 × 89 cm).
If this 1,200 × 900 pixel crop is about 12" (30cm) wide on your screen, then the complete image printed at this same extreme magnification would be about 47 × 70" (119 × 178 cm).
Mechanical Quality performance top
Canon RF 20-50mm f/4L IS USM PZ. bigger.
This is a well-made lens with a metal mount and an all-plastic exterior.
Exterior Finish mechanics performance top
Black plastic.
Hood (included) mechanics performance top
Plastic bayonet.
Front Bumper mechanics performance top
None.
Filter Threads mechanics performance top
Plastic 🤮
Hood Bayonet Mount mechanics performance top
Plastic.
Zoom Ring mechanics performance top
Rubber-covered plastic.
Focus Ring mechanics performance top
Rubber-covered plastic.
Slide Switches mechanics performance top
Plastic.
Identity mechanics performance top
Printed around the front of the lens in nearly invisible dark gray on black, also "20-50" engraved and filled with paint on top of barrel.
Internals mechanics performance top
Can't see!
Dust Gasket at Mount mechanics performance top
Yes.
Mount mechanics performance top
Chromed metal.
Markings mechanics performance top
Except for the serial number and the engraved "20-50" on top of the barrel, everything else is just paint; nothing else is engraved.
Serial Number mechanics performance top
Canon RF 20-50mm f/4L IS USM PZ. bigger.
Laser engraved in invisible black on black on the bottom of the barrel.
Date Code mechanics performance top
The serial number contains a date code.
My serial number starts with 166, which means it was made in June 2026.
Noises When Shaken mechanics performance top
Moderate rattling. This is normal.
Quality mechanics performance top
Made in Japan.
Sharpness performance top
Lens sharpness has nothing to do with picture sharpness.
Every lens made in the past 100 years is more than sharp enough to make super-sharp pictures if you know what you're doing. The only limitation to picture sharpness is your skill as a photographer. It's the least talented who spend the most time worrying about lens sharpness and blame crummy pictures on their equipment rather than themselves. Skilled photographers make great images with whatever camera is in their hands; I've made some of my best images of all time with an irreparably broken camera! Most pixels are thrown away before you see them, but camera makers don't want you to know that.
If you're not getting ultra-sharp pictures with this, be sure not to shoot at f/16 or smaller where all lenses are softer due to diffraction, always shoot at ISO 100 or below because cameras become softer at ISO 200 and above, be sure everything is in perfect focus, set your camera's sharpening as you want it (I set mine to the maximum 7,1,1) and be sure nothing is moving, either camera or subject. If you want to ensure a soft image with any lens, shoot at f/16 or smaller at ISO 1,600 or above at default sharpening in daylight of subjects at differing distances in the same image.
People worry waaaaay too much about lens sharpness. It's not 1968 anymore when lenses often weren't that sharp and there could be significant differences among them; ever since about 2010 all new lenses are all pretty much equally fantastic.
This lens is super sharp corner-to corner at every aperture, limited by your vision as an artist and of course by diffraction at the smallest apertures. Avoid f/16 and smaller unless you really need them for extreme depth of field because diffraction takes its toll. See also How to Calculate the Sharpest Aperture.
Used properly, all of Canon's RF lenses are equally sharp. The differences are in maximum apertures and focal lengths, but none of them are soft if you know how to use them. Lens sharpness has nothing to do with picture sharpness.
MTF at 20mm at f/4. |
MTF at 50mm at f/4. |
RF 20-50mm f/4 IS USM PZ MTF wide-open at f/4 at 10 cyc/mm (black) and 30 cyc/mm (blue). Sagittal (solid) and meridional (dashed).
While it's usually valid to compare rated MTFs between different lenses of similar vintage from the same maker, every maker measures or simply calculates MTF very differently, and therefore one cannot compare these curves between brands. For instance, Sony seems to ignore diffraction and simply calculate overly optimistic MTFs that hug 100%, which no real lens can do at f/8, while other brands are more realistic and include diffraction. Only Canon offers any insight on how they arrive at their curves.
See also my article on MTF and Canon's article on MTFs.
Spherochromatism performance top
Spherochromatism, also called secondary spherical chromatic aberration or "color bokeh," can cause colored fringes on out-of-focus highlights, usually seen as green fringes on background highlights and magenta fringes on foreground highlights.
Spherochromatism is common in fast lenses of moderate and long focal lengths when shooting contrasty items at full aperture.
Spherochromatism goes away as stopped down.
Spherochromatism is seen when the spherical aberration at the red and blue ends of the color spectrum (which together make magenta) is corrected differently than in the middle of the spectrum (green).
Spherochromatism is an advanced form of spherical and chromatic aberration in a different dimension than lateral color fringes and therefore cannot be corrected with software or automatic corrections.
This lens has only a small amount of spherochromatism, with cool fringes behind and warm fringes ahead of the plane of perfect focus. I never saw them in anything other than this deliberate test:
Mondaine A132.30348.11SBB at close-focus distance, Monday, 31 August 2026. Canon R6 V, RF 20-50mm f/4L IS USM PZ at 50mm at f/4 at 1/3,200 at Auto ISO 100, (LV 15.6). bigger or camera-original 32 MP © 4.4 MB JPG file.
1,200 × 900 pixel (5.8× magnification) crop from above. bigger or camera-original 32 MP © 4.4 MB JPG file.
If this 1,200 × 900 pixel crop is about 3" (8cm) wide on your screen, then the complete image printed at this same extreme magnification would be about 12 × 18" (30 × 45 cm).
If this 1,200 × 900 pixel crop is about 6" (15cm) wide on your screen, then the complete image printed at this same extreme magnification would be about 23 × 35" (59 × 89 cm).
If this 1,200 × 900 pixel crop is about 12" (30cm) wide on your screen, then the complete image printed at this same extreme magnification would be about 47 × 70" (119 × 178 cm).
Image Stabilization (IS, OSS, VC or VR) performance top
Optical Image Stabilization (OIS, IS or VR (Vibration Reduction)) works great! I get perfect tripod-equivalant sharpness most of the time at 1/2 of a second at every zoom setting, but only at 1/30 to 1/125 without stabilization!
"Percent Perfectly Sharp Shots" are the percentage of hand-held, free-standing with no support or bracing, frames with 100% perfect tripod-equivalent sharpness as viewed at 300% on a 100 DPI monitor.
Looking at images from my stabilized R6 III at 300% on my 100 DPI monitor from 2½ feet (76cm) away are the same as scrolling around a 15 × 10 foot (4.5 × 3 meters!) print, from just 2½ feet (76cm) away — and images are still perfectly sharp most of the time hand-held at 1/2 of a second. Bravo!
Of course we all will get different results hand-holding. While your speeds will vary, the number of stops of improvement should be the same for all of us regardless of who's shooting or how picky you are about what constitutes "perfect" sharpness.
Hand tremor is a random occurrence, so at marginal speeds some frames will be perfectly sharp while others will be in various stages of blur — all at the same shutter speed. Simply by making several shots and picking a good one, I can get perfect sharpness at one to two seconds hand held!
This rates what percentage of shots are perfectly sharp, not how sharp are all the frames:
On Stabilized R6 III at 20mm
| % Perfectly Sharp Shots | 2s |
1s |
1/2 |
1/4 |
1/8 |
1/15 |
1/30 |
1/60 |
1/125 |
1/250 |
| Stabilization ON | 8⅓ |
42 |
58 |
75 |
86 |
80 |
100 |
100 |
100 |
100 |
| Stabilization OFF | 0 |
0 |
0 |
0 |
0 |
21 |
62½ |
89 |
95 |
100 |
I see 4⅓ stops of real-world improvement.
On Stabilized R6 III at 50mm
| % Perfectly Sharp Shots | 2s |
1s |
1/2 |
1/4 |
1/8 |
1/15 |
1/30 |
1/60 |
1/125 |
1/250 |
| Stabilization ON | 0 |
18 |
75 |
80 |
100 |
100 |
100 |
100 |
100 |
100 |
| Stabilization OFF | 0 |
0 |
0 |
0 |
0 |
3⅔ |
6⅔ |
43 |
87 |
100 |
I see 5½ stops of real-world improvement. Five and a half stops! AWESOME!!!
Sunstars performance top
With a 9-bladed rounded diaphragm, I get really good 18-point sunstars on brilliant points of light at moderate and smaller apertures.
Ignore the crazy rainbow dots around the sun at small apertures; these are sensor artifacts caused by interference among the divisions between pixels on the sensor. These are made visible because we're using enough exposure to show the dark underside of a huge palm tree, and then putting the blinding disk of the mid-day sun in it. Doing this will show everything due to the insane lighting range.
Click any to enlarge:
Click any to enlarge.
Teleconverters performance top
It will not work with any teleconverters.
There is not enough room in the back of the lens to accommodate the protuberances from either of the Canon RF 1.4× or Canon RF 2× extenders.
Weather Sealing performance top
This lens claims weather sealing, but I haven't tried it.
People have worried way too much about this ever since camera companies started FUD campaigns to make us think that our gear will dissolve unless it has weather sealing. How do you think we shot in the rain for the first 200 years of photography?
User's Guide top
Sample Images Intro New Good Bad Missing
Specifications Performance User's Guide
I got my RF 20-50mm PZ at B&H. I'd also get it at Amazon, at Crutchfield or at Adorama, or get it used at eBay (How to Win at eBay), or get it used at KEH.
Zooming
There are two regions on the zoom ring: the conventional 20-50mm range, and a video-like W—T range:
Canon RF 20-50mm f/4L IS USM PZ. bigger.
To get between these two ranges, slide the PZ/MZ (Power Zoom/Manual Zoom) slider to the right (towards the camera) to allow the zoom ring to go from one range to the other:
Canon RF 20-50mm f/4L IS USM PZ. bigger.
Manual-Focus Override user's guide top
Older EOS R cameras need a menu setting changed for manual-focus override, otherwise the focus ring is always ignored in AF. Newer cameras have this set by default.
Find the "Lens electronic AF" or "Electronic full-time MF" option in your AF menu (AF 6 in R5 II, R6 II, R7, R8 and R10, AF 4 in EOS R5 and EOS R6 or CAMERA 8 in EOS RP), and set it to either "One‑Shot‑> enabled," "One‑Shot‑> enabled (magnify)" or ON. Canon should have it set this way by default, but they didn't in older models. No big deal now that I figured it out, and it usually works by default in newer cameras.
Once set, manual-focus override works well in ONE SHOT AF (AF then lock) mode after the camera has finished autofocusing, but in SERVO AF mode all Canon EOS-R cameras as of September 2026 continue to autofocus as soon as you stop turning the manual focus ring! Sadly only Nikon has this all figured out today.
Recommendations top
Sample Images Intro New Good Bad Missing
Specifications Performance User's Guide
Want a full-frame ultrawide-to-normal zoom? Want a full-frame power zoom for video? If either answer is YES!, then this is your lens. Even if not, this is a super sharp, easy-to-zoom lens with superb stabilization, if this is your preferred zoom range.
Personally I prefer the RF 24-105mm f/4L IS USM or the ultralight RF 24-105mm IS STM for the longer zoom range. My very favorite lens is the RF 24-240mm IS USM, but it's bigger. The RF 24-240mm IS USM saves me from carrying a second telephoto, but lacks power zoom for video.
I got my RF 20-50mm PZ at B&H. I'd also get it at Amazon, at Crutchfield or at Adorama, or get it used at eBay (How to Win at eBay), or get it used at KEH.
Be sure to get it only from my recommended sources so that you can just send it back if you don't love it. You never have to guess about how well it will work for you; order it and see for yourself. That's why I've used B&H and Adorama since I was a kid in the 1970s: I can try it in my own environment with my own other gear and if I don't love it, back it goes.
I use a clear (UV) protective filter instead of a cap (exactly like an iPhone) so I'm always ready to shoot instantly. I only use a cap when I throw this in a bag with other gear without padding — which is never. The UV filter never gets in the way, and never gets lost, either.
The very best protective filter is the nearly indestructible Hoya multicoated HD3 67mm UV which uses hardened glass and repels dirt and fingerprints.
For less money, the Nikon 67mm NC (No Color/Neutral Clear), Hoya 67mm NXT Plus UV and Hoya 67mm UV MC are all excellent filters, but the Hoya HD3 is the toughest and the best.
The least expensive coated filter is the Chiaro 67mm 95-UVAT UV, which I haven't tried but ought to be swell.
If I was working in nasty, dirty areas, I'd use an uncoated 67mm Tiffen UV filter instead. Uncoated filters are much easier to clean, but more prone to ghosting.
Nikon's 67mm Circular Polarizer II is excellent.
Filters last a lifetime, so you may as well get the best. The Hoya HD3 stays cleaner than the others since it repels oil and dirt.
All these filters are just as sharp and take the same pictures, the difference is how much abuse they'll take and stay clean and stay in one piece. Since filters last a lifetime or more, there's no reason not to buy the best as it will last you for the next 50 years. Filters aren't throwaways like digital cameras which we replace every few years, like it or not. I'm still using filters I bought back in the 1970s! The Hoya HD3 stays cleaner than the others since it repels oil and dirt, and you'll be using it long after you've thrown this lens away in 50 years.
This 100% all-content, junk-free website's biggest source of support is when you use those or any of these links to my personally approved sources I've used myself for way over 100 combined years when you get anything, regardless of the country in which you live. Canon does not seal its boxes in any way, so never buy at retail or any other source not on my personally approved list since you'll have no way of knowing if you're missing accessories, getting a defective, damaged, returned, gray-market, store demo or used lens — and all of my personally approved sources allow for 100% cash-back returns for at least 30 days if you don't love your new lens. I've used many of these stores since the 1970s because I can try it in my own hands and return it if I don't love it, and because they ship from secure remote warehouses where no one gets to touch your new lens before you do. Buy only from the approved sources I've used myself for decades for the best prices, service, return policies and selection.
Thanks for helping me help you!
Ken.
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Ken.