A telephoto lens is a must-have for photographers, but Canon's RF mount didn't have one until now. Enter the Canon RF 100-500mm f/4.5-7.1 L IS USM. It's the first super-telephoto zoom lens for EOS R-series cameras, giving you 100mm more reach than the popular EF 100-400mm f/4.5-5.6L Mark II DSLR zoom.

Despite the extra reach, the RF 100-500mm doesn't take up more space in your bag than its older DSLR counterpart. It's also slightly lighter. Plus, its in-lens stabilization makes it easier to use handheld, especially with the Canon EOS R5 and EOS R6 bodies, meaning you might not need to bring a tripod on your adventures.

Built solidly as an L-series lens, the RF 100-500mm is weatherproof and comes with handy features like a removable tripod collar and a customizable control ring. It also has a rubber-tipped lens hood with a side window for adjusting variable filters.

Compared to the EF version, the RF 100-500mm has slightly faster autofocus. However, it's worth noting that autofocus speed isn't great with older Canon EOS R and EOS RP bodies but works well with the newer R5 and R6 models.

Teleconverters only work with the RF 100-500mm at 300mm and 500mm focal lengths. Even with a teleconverter, the lens maintains exceptional image quality and performance, typical of Canon lenses.

Canon RF 100-500mm Camera Lens: Features

Currently, there are three telephoto lenses made for the EOS R system, but only one of them is an L-series lens, and it's also the only zoom option. That's what makes the RF 100-500mm f/4.5-7.1 L IS USM special, even though it's pricey.

With its flexible 100-500mm focal length, you have a lot of freedom in composing your images. The lens has six UD (ultra-low dispersion) and one Super UD lens elements that provide strong contrast and sharpness while reducing chromatic aberrations and fringing. Canon's Air Sphere Coating (ASC) helps to prevent flare and ghosting.

Despite being smaller and lighter than the EF version, it's great that the RF 100-500mm has stabilization. It can compensate for up to five stops of camera shake, which goes up to six stops when used with the IBIS system in EOS R5/R6 bodies.

It uses a Dual Nano USM autofocus motor for smooth, fast, and silent focusing. Plus, there's a customizable control ring on the barrel, giving you more control over settings like ISO, aperture, and shutter speed.

Canon RF 100-500mm Camera Lens: Build and Handling

The RF 100-500mm lens offers a wide zoom range but is still quite lightweight and compact. It weighs 1,530g and measures 207.6mm when closed, which is a bit lighter (by 200g) and slightly longer (by about 14mm) than its EF 100-400mm DSLR counterpart. When fully extended to its 500mm focal length, it adds another 9cm in length but still feels balanced when used handheld with an R-series camera.

Just like other L-series lenses, it comes with a large hood that can be locked in place. The hood has a window on the side for adjusting variable filters. It also has a removable and rotatable tripod collar, and it's weather-sealed for use in various weather conditions.

Similar to other RF lenses, there's a textured control ring at the base for adjusting settings like ISO, aperture, and shutter speed. However, unlike non-L series lenses, this ring doesn't have distinct clicks when you change settings. The manual focusing ring is also smooth and lacks hard stops to show minimum or maximum focal distances.

The lens has four switches located conveniently for easy access while shooting. These switches control the focus limiter, autofocus/manual focus, image stabilization, and stabilization modes.

The RF 100-500mm lens uses internal focusing, so the front element doesn't move while zooming, making it compatible with filters with a 77mm ring diameter.

Canon RF 100-500mm Camera Lens: Performance

Testing it with the R5, shooting birds was effortless, with most shots in focus, except when tracking fast-moving birds.

Because the lens has a relatively small aperture range (f/4.5-7.1) at any focal length, it can be tricky to shoot in low light, especially indoors. The new R-system cameras help with this, though, thanks to their better ISO performance.

You can use the lens with older EOS R or RP models, but autofocus might be slower compared to using it with the R5/R6. You can improve this by using the cameras' high-speed burst mode, but it still won't be as fast as with the R5/R6.

If you're using this lens with older Canon mirrorless cameras, you'll appreciate its five stops of image stabilization. Even though it's a bit lighter than the EF 100-400mm, it's still a big lens, so built-in stabilization helps when shooting handheld. We used the lens solely handheld with the R5, and while it did get tiring after about 30 minutes, having six stops of compensation for camera shake meant we got more usable shots than expected.

In short, the EOS R5 + RF 100-500mm f/4.5-7.1 L is perfect for action photography.

Canon RF 100-500mm Camera Lens: Image Quality

The EF 100-400mm f/4.5-5.6L Mark II DSLR zoom is really impressive – it gives top-notch results. The new RF 100-500mm follows suit when used with the EOS R5. The images are super sharp and have beautiful, true-to-life colors.

At longer focal lengths (400-500mm), sharpness at the corners and edges drops a bit, but it's hardly noticeable. If you do see it, you can easily fix it later.

However, the center sharpness remains perfect across the focal range and at almost any aperture. There's no sign of pincushion distortion (where the center of the image looks pinched inward, especially with lines).

Chromatic aberrations – the blue and purple fringing sometimes seen in high-contrast areas – are well controlled at all focal lengths and apertures in real-life shots.

Even though the maximum aperture is slow at f/7.1, the depth-of-field effects are still good. The bokeh looks nice, thanks to the lens having nine aperture blades.

Final Thoughts

The RF 100-500mm lens is a versatile option for Canon's latest R system cameras like the R5 or R6, with fast autofocus and superior low-light performance. Despite its premium price, it offers exceptional versatility for various photography genres. 

Alternatively, the EF 100-400mm Mark II provides beautiful results and can be paired with an RF adapter for cost savings. Consider exploring the RF 600mm and 800mm primes for additional savings, although they have fixed focal lengths and f/11 apertures.

However, the RF 100-500mm may not be ideal for low-light conditions with older Canon R bodies due to slower autofocus speed, limited aperture range, and ISO performance. Consider other options carefully before purchasing this lens.