This Is What $13K Luxury Really Looks Like: Canon RF 600mm F4 Review

Super telephoto lenses have been sluggish to arrive in mirrorless mounts. Yet, Canon already has more long lenses than the older Sony E Mount. That’s partly because lenses like the Canon RF 600mm f4 L IS USM adapt the same optical design as the similar DSLR lens. Telling the new RF 600mm apart from the EF version is difficult to do at first glance. But, with closer inspection, the RF lens has a band of silver at the mount and is actually a little longer and slightly heavier. But, with backgrounds as soft as melted butter, Canon’s new 600mm mirrorless mount is just as made for wildlife and sports as the EF lens.

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There’s a strange feeling that accompanies walking around with more money slung around my neck than the vehicle I arrived in. Priced a penny under $13K, the Canon RF 600mm f4 is certainly a luxury item. The lens used in this review was provided by LensRentals, an option for once-in-a-lifetime shoots for photographers who would otherwise find this lens out of financial reach. I knew exactly where I wanted to shoot when this lens arrived. I packed it the Canon EOS R3 up and headed out to my favorite local birding hotspot. Here’s what I found.

Too Long; Didn’t Read

The Canon RF 600mm f4 is the kind of lens that produces backgrounds so soft, it looks as if it’s a solid color. The super-telephoto focal length mixed with the brighter aperture makes distant subjects pop. The focus is also solid considering how large the lens is. However, it’s heavy and large, and $13,000.

Pros and Cons

Pros

  • Amazing soft backgrounds
  • Solid autofocus
  • Bright aperture
  • Great stabilization
  • Rich colors
  • Minimal aberration and distortion
  • Weather-sealed

Cons

  • Heavy and large (but not the heaviest or largest)
  • Not quite as sharp as shorter L glass
  • $13K at Adorama

Gear Used

I tested the Canon RF 400mm f4 with:

The lens used in this review was rented through LensRentals.

Innovations

Canon says the new RF 600mm f4 is optically identical to the DSLR mount EF 600mm f4L IS III USM launched in 2018. But, while the optical design isn’t new, it shares some harder-to-find controls, including a customizable power zoom ring. Canon also has more super telephoto options available without an adapter than Nikon’s Z mount — and even Sony E Mount. That’s a significant feat, considering the E Mount has been around much longer.

“There’s a strange feeling to walking around with more money slung around my neck than the vehicle that I arrived in.”

Tech Specs

LensRentals lists the following specifications for the Canon RF 600mm:

  • Angle of View: 4° 10’
  • Aperture Blades: 9, Rounded
  • Autofocus: Autofocus
  • Brand: Canon
  • Compatibility: Full Frame
  • Diameter: 6.6”
  • Filter Size: 52.0mm drop-in
  • Focal Length: 600.0-600.0
  • Groups/Elements: 13/17
  • Hood Included: Yes
  • Image Stabilization: Yes
  • Item Type: Lens
  • Length: 18.6”
  • Lens Type: Super telephoto
  • Max Aperture: 4.0
  • Maximum Magnification: 0.15x
  • Mfr. Model Number: 5054C002
  • Minimum Aperture: 22.0
  • Minimum Focusing Distance: 13.8 feet
  • Mount: Canon RF
  • Tripod Collar: Removable and Rotating
  • Weight: 6.8 lbs.

Ergonomics

The Canon RF 600mm isn’t just a piece of optical luxury. No, this lens also doubles as workout equipment. Train this nearly seven-pound lens on a distant bird, then hold that pose and wait for the bird to do something interesting while your arm muscles burn. Or, for a full-body workout, crouch and brace your elbows on your knees for a steadier shot that spreads the burn throughout the arms, core, and legs.

I jest, but only a little bit. According to my Apple Watch, I’ve never burned as many calories on a photo hike on flat ground as I did hauling the Canon RF 600mm. The lens hood alone is as big as my face. The lens itself is 18.6 inches long. On my petite five-foot-two frame, with this hanging from the camera neck strap, the end of the lens hood reached down to my shins. While it’s large, it is possible to shoot handheld. But possible isn’t the same thing as comfortable. You’ll want either a monopod, a tripod, or regularly scheduled visits with a chiropractor.

It won’t fit in many camera bags — thankfully, it ships with its own lens case. While most “free” lens cases are just a bit of velvet, the case with this lens is actually nice and includes a sling strap to wear the case on your back. It sells on its own for $440, but is included with this lens.

While I’m complaining about the size of this lens, it’s actually not bad for a super-telephoto with a bright aperture. Nikon’s F-mount 600mm f4 weighs 8.4 pounds. Sony’s weighs 6.7 pounds. It’s actually slightly heavier than the Canon EF 600mm f4L IS II USM, which weighs 6.71 pounds. It’s not the heaviest 600mm out there, but if you’ve never shot a 600mm f4 prime before, prepare to huff a little if you hike with it.

Now that I’ve poked fun at the size of this cannon — err, I mean Canon — let’s move on to the controls. Closest to the mount are two silver buttons at the top of the lens. This pulls out to drop in 52mm filters. While the cost of a filter on a $13K lens isn’t a big issue, I’m really glad you don’t have to find filters the size of a salad plate to fit on the front it.

The first bank of controls near the left hand houses two switches for focusing: the focus limiter switch and, on top of that, the AF to MF switch. Unlike most AF-MF switches, this also has a PF mode. The PF mode allows the small playback ring to change the focus using power focus. This is a feature more geared towards video, with smoother, faster focus changes.

After those controls, the lens widens out a bit. The tripod ring sits here. The ring is a good size and balances on a flat surface when the R3 is attached. There are two different screw-in mounts on the bottom.

Next is another bank of controls, this one with four switches and two buttons. The top switch has a stabilizer mode; the second turns stabilization on and off. Mode one is general stabilization, mode two is for panning, and mode three only activates stabilization when the shutter is pressed (which means the view from the viewfinder is not stabilized).

Below these stabilization controls are additional focus controls. The set button and the focus preset switch (which has off, on, and on with sound), allow you to preset two focal lengths and quickly switch back and forth between the two. The final switch allows you to customize the speed of the manual focus ring, with three different settings.

Next is the large, grippy black focus ring. That’s followed by the narrower playback ring, which alternates between the two focus presets or acts as a power focus ring. The next black ring isn’t actually a physical ring but rather a thin strip of grippy material. Four buttons evenly spaced here are AF stop buttons. Pressing and holding one of these buttons temporarily pauses autofocusing.

The front of this lens is as large as a salad plate. It’s all glass, with little plastic edging to speak of. Since the front is so large, it ships with a soft cloth lens cap rather than the traditional plastic ones. That, along with the lens bag, is much nicer than you’d typically find with lenses that don’t cost five figures.

The Canon RF 600mm f4 is a large, heavy lens with plenty of physical controls. It’s not impossible to hike with: I took this about two miles around one of my favorite birding spots. It’s also not the heaviest 600mm f4. But, it’s ergonomically best for sitting in a blind and waiting for wildlife or standing on the sidelines of a sports game.

“The Canon RF 600mm isn’t just a piece of optical luxury — no, this lens also doubles as workout equipment.”

Build Quality

The lens feels great in the hands. I don’t want to feel how much heavier the lens would be if it were metal. But, it’s not the cheap-feeling plastic. The look and feel live up to the L series standard.

As an L series lens, the RF 600mm F4 is dust and weather resistant with seals on the mount, switches, and rings. I didn’t have the opportunity to test it in the rain. I gave it a good splash with a cup full of water (while my hand was shaking a bit because yes, I know just how much this lens costs). The lens kept shooting just fine, with all the rings and switches functioning normally. I also didn’t notice dust on the sensor; the R3 has the shutter closing between lens swaps which also helps.

Autofocus

The Canon RF 600mm f4 is capable of focusing as close as about 13 feet from the front of the lens. On a 600mm, that gets in nice and close and offers some spectacular background blur as a result.

As I expected, focusing a lens that’s nearly as tall as my toddler is no easy feat. That’s just simple physics; moving so many parts along such a great distance is a challenge. Thankfully, Canon is up to the challenge. Birding with this lens, the 600mm missed less than five percent of the time. Some of those misses were user errors or branches in the way. Some were fly-by birds where I couldn’t lock focus quickly enough, though the lens also had plenty of sharp fliers as well.

The trick that I’ve found to focusing with this lens is to avoid going from one extreme to the other. The lens had the most trouble when focusing on a distant bird then switching focus on a much closer bird. The focus limiter switch will help here. Or, I found focusing on the trunk of the close-up tree before training the lens on the nearby bird also worked well. Focusing on a small subject while also moving from infinity to a much closer focal distance was the most challenging for this lens. But, especially paired with the R3’s animal eye detection, this lens will keep up with movement 95 percent of the time.

Ease of Use

A $13,000 lens isn’t a beginner’s lens. There are several physical controls on this lens. Even after using other Canon lenses in the past, I still had to dig into the user manual to learn what the playback ring was and how to set the focal distances to quickly switch between the two.

But, once you spend the time learning those controls, those options will help photographers get the most out of such a lens. The playback ring or the focus limiter switches will help switch from one extreme focal length to the other efficiently. 

The other challenge to this lens, of course, is the size. It won’t fit in many camera bags. The 600mm is bulky and heavy to carry around. The 6.8 pounds doesn’t sound like much until you try to hold that weight steady for several minutes. It’s also a bit awkward to mount. I found it easier to twist the camera body instead of twisting the lens in place.

“Birding with this lens, the 600mm missed less than five percent of the time. Some of those misses were user error or branches in the way.”

But, while heavy and super-telephoto, the stabilization system makes it possible to shoot without a tripod. (If you have the arm strength for it, anyway.) When birding, the blur from the movement of the birds came well before any blur from camera shake (though shake did creep in on a few images). Of course, lenses made for birding and sports are going to be used at those higher shutter speeds most often anyways. I spent most of my time above 1/600. The stabilization system at least allows such a heavy lens to still fit within the reciprocal rule. The monopod I used was largely for my own comfort and not because the stabilization system couldn’t handle such a big, long lens.

Image Quality

The photos from the Canon RF 600mm f4 are the prize for wielding that heavy glass. The super-telephoto focal length mixed with the f4 aperture creates an effect that’s difficult to do with other optics. The 600mm makes objects feel closer together. And the f4 aperture creates a shallow depth of field. Together, the combination gives images an entirely different feel; objects pop more while backgrounds blur into nearly a sold color. 

I knew exactly where I wanted to go with a 600mm lens: an island where blue herons make their nests every year. I’ve shot in the same location with a 100-500mm telephoto and the branches typically look flat, as if they could all be from the same tree. The 600mm f4 separated the clump of trees, giving them more dimension. While distant subjects like that feel more 3D, the lens created beautiful, nearly solid-colored backgrounds on closer wildlife.

Bokeh

This is the kind of lens that makes wildlife appear almost as if it were shot against a studio background. The long focal length and bright aperture, with closer subjects, blur the background into one solid color. On further subjects, objects appear to have more depth. The out-of-focus elements seem to have almost a painterly feel to them.

Cropped

The out-of-focus highlights are typically soft and round, without a hard edge. Smaller, brighter highlights, such as splashes of water occasionally have more of an edge and a slight soap bubble look to them.

Sharpness

As a prime lens, the RF 600mm f4 has a nice level of sharpness to it. It’s not overly sharp; I’ve seen sharper shorter primes. Pixel peeping, the center isn’t quite as sharp as some of the shorter RF primes that I’ve tested. And I do have to wonder if some of that is using the same optical design as the EF lens. But the center is sharp and the corners have little fall off, even shooting at wide open. I shot this lens at f4 most of the time. And while my test chart wasn’t quite as sharp, for real-world shots, I didn’t notice any significant loss in detail.

Lens Character

The RF 600mm f4 has little corner bending, I didn’t spot obvious pincushion or barrel distortion. Similarly, chromatic aberration was difficult to find and high contrast areas such as the edges of tree branches looked pretty clean in the RAW files. You can find some aberration in backlit areas, but it’s minor and you’ll only find it when pixel peeping.

Pointing this lens at the sun creates soft white flare blooms rather than colorful dot flare. It’s a nice soft effect and there’s still a bit of contrast left.

Color Rendering

The colors from this lens feel rich, yet realistic. The colors didn’t feel over or under-saturated, but I preferred images that were slightly under-exposed. Colors with just a bit of underexposure look very rich. Without obvious aberration to interfere, the colors look very clean. Well-exposed images with the sky as the background had a nice light feel to them.

Extra Image Samples

From day one, The Phoblographer has been huge on transparency with our audience. Nothing from this review is sponsored. Further, lots of folks will post reviews and show lots of editing in the photos. The problem then becomes that anyone and everyone can do the same thing. They’re not showing what the lens can do. So we have a section in our Extra Image Samples area to show edited and unedited photos. From this, you can make a decision for yourself.

Edited

Unedited

Conclusions

Likes

  • Images have great depth, rich colors, and super soft backgrounds.
  • Even with such a large lens, the autofocus is still excellent.
  • The stabilization makes it possible to handhold this lens, even though it’s heavy.
  • There’s minimal aberration or distortion to complain about.
  • This lens is weather-resistant and has plenty of physical controls.

Dislikes

  • Its size and weight make this lens difficult to hike around with.
  • I’ve seen a bit more sharpness from shorter L mount lenses.
  • That price is tough to swallow: $13K at Adorama.

The Canon RF 600mm f4 is a heavy, expensive lens. Yet, the images are worth hauling such a large optic around, with rich color, soft backgrounds, and close detail. The autofocus keeps up 95 percent of the time and the image stabilization makes it possible to shoot handheld (though still uncomfortable). The large lens was a conversation starter among other bird photographers, so perhaps it is not ideal for introverts.

Would I buy this lens? Well, I would have to make a genre change from a wedding photographer to a professional wildlife photographer. As a hobbyist, the price is simply too much to justify. The lens is also harder to hike with than a 100-500mm, even though the 600mm carries a much different look to it. But it’s an impressive lens, particularly when paired with the R3.

One last thing to note; it’s optically similar to Canon’s EF mount 600mm. Owners of that previous lens likely won’t find a noticeable difference in image quality. I can’t say for certain, however, how well adapting the older EF lens will work with autofocusing.

Rating: 5 out of 5.

I’m giving the Canon RF 600mm f4 five out of five stars. Want one? Check them out for $13K at Adorama or rent it at LensRentals.

Hillary Grigonis

Hillary K. Grigonis is a photographer and tech writer based in Michigan. She shoots weddings and portraits at Hillary K Photography. A mother of three, she enjoys hiking, camping, crafting, and reading.