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Underwater we rarely shoot straight lines, so the distortion of a fisheye lens usually isn’t a problem. However, being able to get closer to our subjects leads to sharper, more colorful, and more contrasty images (Canon EOS R5 Mark II, Canon RF 7–14mm f/2.8–3.5L Fisheye, Nauticam housing, Nauticam 230mm acrylic dome, dual Backscatter Hybrid Flash strobes, f/13, 1/250s, ISO 400)
 

A new fisheye lens is always a big deal for the underwater photography community. Back in the early 2010s, Canon was first to modernize its fisheye offering by introducing the Canon EF 8–15mm F/4L Fisheye, a zoom-through lens that essentially offered two usable focal lengths to full-frame camera users: a 180° diagonal field of view at 15mm, and a 180° circular fisheye image at the 8mm end.

Needless to say, most photographers were only using it at the 15mm end, but even so, it offered a meaningful upgrade over existing fisheye lenses in terms of detail rendition, contrast, focusing speed, and minimum focus distance, which allowed the use of mini-domes for close-focus wide-angle photography.

In 2017, Nikon followed suit with its own 8–15mm F-mount fisheye. Since then we’ve had years without a new fisheye truly suitable for underwater photography. (The 2024 Sigma 15mm f/1.4 DG DN Diagonal Fisheye Art, for instance, has a minimum focus distance of 38cm, which simply doesn’t work behind a dome port.) Meanwhile, mirrorless shooters had no choice but to adapt older DSLR fisheyes.

That all changed in February 2026 when Canon struck again with a new fisheye natively built for its mirrorless RF cameras—the Canon RF 7–14mm f/2.8–3.5L Fisheye STM. Keep scrolling to read my underwater field review after using it over the past three weeks to photograph temperate reefs, a wreck, and some playful fur seals in southeast Australia.
 

The topside portion of Clifton Gardens Jetty in Sydney is rarely visible from the bottom, but on that day I enjoyed glorious visibility of 6 or 7 meters… and I could capture the sandy seabed and the surface in one circular frame at 7mm (top). When zooming in at 14mm (bottom), I would have had to back off to capture the whole jetty in one shot (Canon EOS R5 Mark II, Canon RF 7–14mm f/2.8–3.5L Fisheye, Nauticam housing, Nauticam 140mm dome, f/16, 1/320s, ISO 800)

Physical Differences with the Canon EF 8–15mm Fisheye

Compared to its predecessor, the new RF fisheye is lighter (16.8oz/476g vs 19oz/540g) but a bit longer (4.3in/109mm vs 3.27in/83mm), though it doesn’t extend while zooming. You’ll need a different port extension when upgrading from the EF 8–15mm Fisheye. If you’re a Nauticam shooter like me, that means moving from a 30mm to a 20mm port extension.

The new lens features a zoom limiter switch intended for cropped-sensor users. This limits the zoom range to 9–14mm, which is where the lens delivers uninterrupted zoom-through diagonal fisheye coverage for APS-C camera users—or when using your full-frame camera in crop mode.

There’s also a slot at the rear of the lens for Canon’s drop-in filters. This can be useful for split shots if you want to darken one half of the frame using a graduated neutral density filter. (Note that Canon’s EF-to-RF mount adaptor also accepts drop-in filters, so the same functionality is available when shooting the EF 8–15mm Fisheye on an RF camera.)
 

Upgraded Focal Range

Perhaps the specification that creates the most confusion around this lens is the 1mm shorter focal range. If the Canon EF 8–15mm Fisheye already covered a 180° diagonal field of view at the 15mm end, what sort of field of view do we achieve at 14mm? The devil lies in the details: While the original 8–15mm fisheye lens did cover 180° at 8mm in circular fisheye terms, at the 15mm end, it actually “only” achieved a diagonal field of view of 175.5°.

Conversely, at 14mm, the new RF fisheye lens offers a true 180° diagonal FOV, and at the 7mm end, a mind-boggling 190° circular field of view. Yes, that means the lens can literally see behind its front optic, so you’ll need to keep that in mind if you don’t want your fins appearing in the frame!
 

A complete 180° diagonal field of view is available at the longest end of the zoom range, allowing me to easily fit this crested hornshark and the setting sun in the frame (Canon EOS R5 Mark II, Canon RF 7–14mm f/2.8–3.5L Fisheye at 14mm, Nauticam housing, Nauticam 140mm dome, dual Retra Flash Pro Max II strobes, f/13, 1/50s, ISO 400)
 

I used the same 140mm Nauticam glass dome port that pairs well with the older 8–15mm fisheye, albeit with a different extension, and as far as I can tell, this gives access to the complete 190° circular field of view, including the tip of my fin at the bottom! (Canon EOS R5 Mark II, Canon RF 7–14mm f/2.8–3.5L Fisheye at 7mm, Nauticam housing, Nauticam 140mm dome, f/10, 1/125s, ISO100)
 

The blue color fringing visible in the above photo is present in all of my images shot at 7mm, whether topside or underwater. Unfortunately, Lightroom’s automated lens corrections do not remove it. Since the color may closely match your water background, correcting it in post-processing can require both know-how and patience. It would be great to see either a dedicated plugin or an updated correction profile released for this lens to deal with the issue.
 

Shooting uninterrupted 190° circular fisheye requires taking off your dome’s outer shade, which I did for my 140mm Nauticam glass dome
 

Clearly, most users will only shoot this lens at the 14mm end for the full 180° diagonal fisheye field of view. Interestingly, when I unintentionally zoomed out to 13mm, I found that my photos taken with the Nauticam 140mm glass dome showed no vignetting, although the shade of my Nauticam 230mm acrylic dome port appeared in images taken at that focal length. It may be that the lens offers an even wider diagonal fisheye field of view—185° or maybe 190°?—at the 13mm position, but this isn’t officially supported in Canon’s documentation, and I’d urge you to check your photos regularly if you want to take advantage of it.

All in all, the new RF 7–14mm f/2.8–3.5L Fisheye does offer a wider field of view than its predecessor, which will come in handy for big animals as well as scenic reef and wreck photography.
 

Both of these images were shot at 13mm and uncropped. Top: Not a lens hood in sight with the Nauticam 140mm dome (f/11, 1/125s, ISO 200). Bottom: With the Nauticam 230mm acrylic dome, the shade shows up on the right-hand side of the frame (f/16, 1/250s, ISO 500)

Image Quality

Aside from the blue color fringing mentioned above at the 7mm end, I found the image quality of this lens to be nothing short of excellent. The EF 8–15mm Fisheye was already well regarded in the underwater imaging community for offering improved sharpness and colors compared to other full-frame fisheyes available at the time, but the new RF-mount fisheye lens is designed to further improve contrast and sharpness towards the periphery of the frame.
 

Top: A wobbegong lies motionless on the Tuggerah Wreck (Sydney, NSW, Australia). Bottom: 100% crop of the same photo. I am fully satisfied with the sharpness of the shark’s mouth appendages! (Canon EOS R5 Mark II, Canon RF 7–14mm f/2.8–3.5L Fisheye at 14mm, Nauticam housing, Nauticam 230mm acrylic dome, dual Retra Flash Pro Max II strobes, f/16, 1/250s, ISO 500)
 

When comparing underwater photos taken with both lenses, the difference doesn’t exactly jump out immediately, but as we know, water naturally reduces contrast and fine detail underwater. In any case, the EF 8–15mm Fisheye launched at a time when Canon’s highest-resolution full-frame sensor was 22 megapixels (Canon EOS 5D Mark III), and the RF 7–14mm Fisheye is clearly designed to better cope with current and future high-resolution cameras.

Notably, the RF 7–14mm Fisheye also features Canon’s latest anti-reflective coatings, which do an excellent job of keeping flare to a minimum, even when shooting directly into the sun.
 

My son Alex modeling for me in a Sydney rock pool. While flare is very well controlled by the lens itself, depending on the dome you use, you might still see reflections of the lens when shooting straight into the sun. I wonder whether a drop-in polarizing filter could help reduce this, but I haven’t had the chance to try one yet. On another note, I quite like the appearance of the sunstar (Canon EOS R5 Mark II, Canon RF 7–14mm f/2.8–3.5L Fisheye at 14mm, Nauticam housing, Nauticam 140mm glass dome, dual Retra Flash Pro Max II strobes, f/22, 1/250, ISO 250)

Aperture

While its predecessor offered a constant maximum aperture of f/4 throughout the zoom range, the new RF fisheye lens opens up to f/2.8 at the 7mm end and still offers a modest improvement of f/3.5 at the 14mm end. Perhaps more interestingly for underwater photographers, the minimum aperture at the diagonal fisheye end improves from f/22 to f/29, which may come in handy for over-unders or creative slow-shutter shots.
 

Autofocus

The RF fisheye lens uses Canon’s newer STM technology, designed to deliver quieter, smoother and more precise autofocus, which will be appreciated by videographers. All in all, behind a dome port, the lens focuses on a virtual image that is much closer than the real subject, meaning the optics don’t need to move as much.

The EF 8–15mm Fisheye already provided a very good hit rate even with fast-moving subjects. I’ve now taken over 2,000 fur seal photos with the RF 7–14mm Fisheye, and I can count on my fingers—perhaps with a few toes too!—the number of images where autofocus missed. Most of those failures occurred when the subject was strongly backlit by the sun, a scenario that still causes trouble for modern mirrorless cameras.
 

I can’t think of a better autofocus test for the new fisheye lens than the cheeky Australian fur seals that live on Montague Island, NSW, Australia (Canon EOS R5 Mark II, Canon RF 7–14mm f/2.8–3.5L Fisheye at 14mm, Nauticam housing, Nauticam 230mm acrylic dome, dual Retra Flash Pro Max II strobes, f/16, 1/250s, ISO 500)

Flexibility

I’ll state the obvious: For a full-frame camera user, this new fisheye lens remains essentially a two-lenses-in-one setup. The intermediate focal lengths aren’t really usable—no one wants their photos to look like a cropped circle! However, if you intend to use this lens with an APS-C camera such as the Canon EOS R7, you’ll be pleased to know that full diagonal fisheye coverage starts at 8.7mm—there’s a mark on the zoom ring. This means the entire 8.7–14mm focal range is fully usable, offering versatility that approaches the much-loved Tokina 10–17mm—albeit with much improved image quality.

Back in the DSLR days, Canon full-frame shooters had the option of mounting a Kenko 1.4x teleconverter behind the EF 8–15mm Fisheye to obtain a similar usable zoom-through range, greatly increasing the lens’ versatility from the biggest subjects down to close-focus wide angle. At the time of writing, however, there are no teleconverters compatible with the RF 7–14mm Fisheye. Canon’s own teleconverters are designed for telephoto lenses with front elements that protrude too far forward, and no third-party manufacturer has yet come to the rescue.
 

A number of my seal photos have a 20–30% crop. It would have been nice to have a teleconverter to zoom in tighter than 180° of diagonal field of view (Canon EOS R5 Mark II, Canon RF 7–14mm f/2.8–3.5L Fisheye at 14mm, Nauticam housing, Nauticam 230mm acrylic dome, dual Retra Flash Pro Max II strobes, f/13, 1/250s, ISO 200)

Virtual Reality Applications

Interestingly, Canon positions the RF 7–14mm Fisheye as compatible with its EOS VR ecosystem, allowing photographers to convert single fisheye images into “2D VR” content viewable on compatible devices. Unlike the older EF 8–15mm Fisheye, the new lens was specifically designed with this workflow in mind, with the wider field of view and improved edge sharpness intended to enhance immersive viewing. I tried converting a few of my still photographs into the 2D VR format using the Canon EOS VR Utility software (subscription-based, with the first month free), then viewed them on my Meta Quest 3 VR headset.

With the headset on, it felt a like viewing my photos on a gigantic curved screen. Close-focus wide-angle photos taken at the 14mm end produced the strongest wow factor, but I didn’t find the 7mm circular fisheye benefitted from this sort of projection. Note that Canon also sells dual fisheye lenses capable of creating true 3D VR stills and video footage. I’d love to see a housing port designed to take these underwater!
 

I tried converting a few of my still photographs into 2D VR format using Canon’s EOS VR Utility software, and then viewed them on my Meta Quest 3 VR headset. Top: original image. Bottom: the “warped” 2D 180° version

Who Is the Canon RF 7–14mm Fisheye for?

If you’re a Canon RF shooter and own the EF 8–15mm Fisheye with an EF-RF adaptor, then you already have a lens that can essentially do the same thing as the 7–14mm. Images taken with the two lenses don’t look dramatically different. In that case, I’d mainly upgrade if you regularly find yourself wanting an even wider field of view than the 175.5° you’re getting at 15mm. If you plan on shooting fisheye video, the RF lens’ newer STM autofocus system is another good reason to upgrade, offering smoother and quieter focus transitions than the previous USM drive.

If you shoot Canon RF and don’t already own an EF 8–15mm Fisheye, then you should absolutely consider investing in the RF 7–14mm Fisheye. A fisheye is an extremely useful lens for wide-angle photography. The only real downside comes with shy subjects, since you need to get very close to fill the frame.

Finally, if you’re an RF cropped-sensor user, the incentive to buy the RF 7–14mm Fisheye is arguably even greater. You’ll get a true 180° diagonal fisheye plus genuine zoom-through capabilities for maximum versatility. A second-hand Tokina 10–17mm Fisheye would provide a more affordable alternative, but with lower image quality.
 

The RF 7–14mm Fisheye lends itself nicely to over-unders (Canon EOS R5 Mark II, Canon RF 7–14mm f/2.8–3.5L Fisheye, Nauticam housing, Nauticam 230mm acrylic dome, f/16, 1/250s, ISO 400)

Final Thoughts

A fisheye used to be my go-to underwater lens. While transitioning from one system to another, I even spent a few years without owning any other wide-angle lens. Over the last couple of years though, I’ve relied heavily on Nauticam’s wet optics—namely the Wide Wet Lens C (WWL-C) when compactness mattered and the Fisheye Conversion Port 1 (FCP-1) when I needed a wider field of view. Yet, there are still a few things that only a (dry) fisheye lens can offer: a true 180° field of view; huge, forgiving depth of field; good corner sharpness at “reasonable” apertures; and a compact footprint. Besides, fisheyes are simply better suited to split shots when paired with a large dome. These are all very good reasons to add one to your arsenal.

Personally, I would have preferred a smaller and more affordable fixed diagonal fisheye, or a zoom-through diagonal fisheye (something like 14–21mm), but I applaud Canon’s decision to invest the R&D resources into modernizing its fisheye offering and bringing on board the technological advances in lens design from the past 15 years.
 

The author would like to thank Abyss Scuba Diving for taking him to Sydney’s iconic Tuggerah Wreck and Underwater Safaris for some exhilarating seal dives off Montague Island.
 

About the Reviewer: Nicolas Remy is an Australia-based pro shooter and founder of online underwater photography school and community, The Underwater Club, with members in 18 countries. He serves as an ambassador for Mares and Nauticam, and chairs the jury of the prestigious DPG Masters photo competition. Nicolas’ images have been widely published in print and digital media, and have won over 40 international photo awards. To see more of Nicolas’ work or browse his upcoming workshops, visit: www.nicolaslenaremy.com.

Canon RF 7–14mm Fisheye

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