An underwater review of the Canon EOS R5 mirrorless camera

Without a doubt, the Canon EOS R5 is the top image-maker of 2020 and could potentially go unmatched in the camera world for another few years. It is the first full frame mirrorless camera to offer 8K video capability and features a specs sheet that puts it at the top of its class. The EOS R5 directly answers many of the concerns that photographers had with the EOS R and promises significant updates to important functions including autofocus, stabilization, continuous burst shooting, and video.

Despite Sony’s dominance in the underwater camera market over the last year with the A7R IV, it is likely that the Canon EOS R5 will be even more popular as the camera of choice for both underwater photographers and filmmakers.

Some lucky individuals on our staff at Bluewater Photo were given the opportunity to capture some of the first underwater photos and video with the Canon EOS R5 early. After braving long drives, difficult shore entries, long swims, windstorms, and post-apocalyptic levels of wildfire smoke, we feel quite confident that we put this camera to the test in the harshest conditions the Pacific Northwest has to offer. The R5 is currently leading our best Canon cameras guide.

We also feel confident in saying that the Canon EOS R5 might just be our favorite camera we’ve ever shot underwater. Yes, that’s right. Say goodbye to your Canon DSLRs, Nikons, and Sonys. With the R5, Canon has reached the ultimate balance of great glass, great resolution, great autofocus, great dynamic range, and pretty much great everything.

Although Canon got everything right with the R5 from the ergonomics to the performance, they also got one important thing wrong – their marketing. After the original flop of the Canon EOS R, Canon’s marketing department got the memo that specs matter and took the mantra to the extreme. By January of 2020, the R5 had garnered a cult-like following drooling for 8K video, internal RAW recording, and 4K @120p.

Yes, the R5 does all these things, but with limited availability. Before you read this review, please unread anything you may have read about this camera. While the R5 is a great video camera, it is, in fact, the very best stills camera on the market for underwater photography.

So, think of it as a stills camera first, with amazing hybrid video capability. It is not a dedicated video camera.

Canon EOS R5 Compared with Canon EOS R

The Canon EOS R was Canon’s first attempt at a full-frame mirrorless camera. With many good options from Sony and Nikon, it fell short. Fortunately, the Canon EOS R5 addresses many of the concerns that Canon EOS R users brought up. Though I would like to interject and say that the Canon EOS R was one of our favorite cameras that we tested underwater.

For underwater photography, Canon was lagging behind Sony and Nikon because of the lack of in-body image stabilization. The EOS R5 is Canon’s first camera with IBIS, capable of 7-8 stops of correction when combined with a stabilized lens. The EOS R5 also features a new 45 MP CMOS sensor – addressing concerns that the EOS R was not a high enough resolution for professionals. Furthermore, the EOS R5 has the capability of shooting 12 frames per second with the mechanical shutter (20 fps electronic), vs the 8fps on the EOS R! Did we mention dual card slots?

For underwater videography, Canon fell short of its competitors with its original EOS R by offering cropped 4K video. The EOS R5 not only goes above-and-beyond addressing these concerns – it is industry-changing. The EOS R5 is capable of capturing 8K 10 bit 4:2:2 @ 30p RAW video recorded internally – and it has the option of recording in 4K ProRes RAW externally simultaneously. The camera is also capable of 4K video using the full width of the sensor at an amazing 120p! The R5 can capture video with dual pixel autofocus, full AF in all modes. The EOS R5 is one of the first consumer-level cameras to offer 8K video, so it’s already a very popular camera for underwater video.

Canon EOS R5 Specifications

Sensor	45-megapixel full-frame CMOS
Lens Mount	Canon RF
Max resolution
File format	RAW, JPG
Bit-depth	14-Bit
ISO	100-51,200
Stabilisation	5-axis in-body image stabilisation works with IS lenses
Continuous shooting	12fps (mechanical)
8K Video	8K DCI (8192 x 4320) & 8K UHD (7680 x 4320) at up to 29.97fps RAW / 4:2:2 10-Bit
4K Video	4K DCI (4096 x 2160) & 4K UHD (3840 x 2160) at up to 119.88fps / 4:2:2 10-Bit)
HD Video	Full HD (1920×1080) at up to 240p
Focus type	Dual Pixel CMOS AF (also available in 8K and 4K video modes)
AF Points	1053 phase detection
Viewfinder	5.76m-dot EVF
LCD	3.0″ 1.04m-dot Articulating Touchscreen LCD
Card slots	Dual CFexpress and UHS-II SD
Connectivity	WiFi, Bluetooth
Dimensions
Weight
Launch price	$3,899

Canon EOS R5 Key Features

Body, Build, Ergonomics, and Battery Life

We find the build of the Canon EOS R5 to be a little more plasticky than we would like. But when we first got the R5 in our hands, we were amazed at how small the body was considering its video processing capabilities. No wonder there are recording limits! If you want 8K video from a body this small, there are going to be some compromises.

The weather sealing on the camera is great. At one point during our tests, we needed to open the housing on the beach and we felt confident that the camera would be ok – even after a little sand and water dropped onto the body. We don’t recommend it, of course, but the camera is pretty solid for most conditions you might find on a dive trip.

The Canon EOS R5 is built similarly to the EOS R and EOS R6. As a mirrorless camera, it’s a tad bit smaller than its DSLR counterparts. But it’s still a substantial camera with a nice grip. In most cases, due to the size of RF and EF glass, underwater housing manufacturers will need to use their DSLR port systems. Full EOS R5 underwater systems are about the same size as a DSLR system, despite the added size benefits of mirrorless cameras. For most manufacturers, we expect the EOS R5 to need a separate housing from the R6 and EOS R.

The button placement on the camera is well thought-out and the ergonomics of the EOS R5 are excellent. In fact, the ergonomics just might be the best in its class of mirrorless camera across all brands. Canon discontinued the use of the touch bar that many found annoying on the original EOS R. They replaced it with the classic joystick control and added a wheel to the back of the camera, instead of a D-pad.

We think these button improvements make it an even more compelling camera from the standpoint of useability – clearly surpassing the Sony A7R IV. This is especially the case if you do a lot of topside shooting as the joystick is a breeze to use above water. However, many underwater housings will not support the joystick, which will leave underwater shooters with the dials to control their settings underwater instead of the D-pad. This can take some getting used to, but we found that it actually made switching settings a bit quicker once the muscle memory was built into our fingers.

The battery life of the EOS R5 is acceptable. It could be better, but it will be enough for almost a whole day of diving if you are just taking photos. We found that we could get about 3 dives out of one battery taking both photos and videos (about 200-300 photos and 6-8 minutes of video). If you are just taking video, the battery life is about one hour (i.e., one to two dives).

Video Overheating Concerns

Although the EOS R5 has a lot to brag about when it comes to video specs, there is a major caveat. Because of the camera’s smaller size and extreme processing power, we actually think the EOS R5 was built a little too small for its spec sheet. Canon ultimately decided not to include a dedicated cooling system in the body – in favor of portability – leading to some issues with overheating while shooting 8K video or high frame rates. Canon has been forthcoming about the exact runtime limitations of the body due to heat with a statement back in July and a new firmware update in August.

At 8K, the EOS R5 will be able to record for about 20 minutes at room temperature until it needs to shut down for 10 minutes before it can shoot one minute of video again. After that, it can record for a maximum of 3 minutes unless there is a longer wait period. The camera won’t fully reset unless it turns off for about half an hour. At 4K and 120 fps, the max run time at room temperature drops to 15 minutes. This will be a concern for warm water divers, and we do recommend adding silica desiccant packets to and underwater system to prevent fogging. Coldwater underwater photographers and videographers may fare better with this camera.

To obtain a more accurate assessment on how bad the overheating issue may be for underwater videographers, we decided to put the Canon EOS R5 through an underwater overheating test. The overall assessment was that an underwater videographer should have approximately 20-25 minutes of consecutive or nonconsecutive video during a dive at 8K @ 30p with internal RAW recording and slightly less time with 4K @ 120fps.

Due to the recovery times that are necessary before you can shoot video again, once the camera reaches its overheating limit, it is essentially done for the dive. For most photographers and hybrid shooters, this won’t be an issue. However, serious video shooters may want to consider the A7S III if they need those high frame rates. Fortunately, 4K @ 60p shouldn’t cause issues with overheating during a dive and we recommend shooting at that resolution and frame rate anyway.

Check out the full results we got during our overheating test

Note: Photographers should not be concerned about the overheating issue. The Canon EOS R5 does not overheat when taking photos!

Improved Image Quality and Processing

The Canon EOS R5 is Canon’s first high resolution, full-frame mirrorless camera. They designed a 45 megapixel, full-frame CMOS sensor specifically for the R5. The original 30 megapixels in the Canon EOS R didn’t quite cut it for us when we compared it to other cameras like the Nikon Z7 and Sony A7R IV. An extra 15 megapixels puts the R5 firmly in the “high-resolution class” – ideal for large prints, macro crops, and all-around mouth-watering photography.

For underwater photographers who are considering the EOS R5 for the high-resolution sensor, we should mention that more megapixels can add noise in some situations – especially low light photography. However, we really didn’t find this to be an issue when we took photos with the R5 like it was with the A7R IV. The images were all very clean, even at slightly higher ISOs. Any noise that we got in our images was fine-grained and easy to remove in post. If you are looking for amazing, sharp images in a high performing stills camera, we think the Canon EOS R5 is second to none – especially when paired with Canon’s amazing lineup of RF and EF lenses.

The Canon EOS R5 is equipped with the same DIGIC X processor used in the 1DX Mark III. Certainly, the processing power is the key to the 8K video and amazing 12 fps/20 fps electronic frame rates boasted by Canon. Due to this processing power, the R5 is also capable of a 180 shot RAW image buffer. At 20fps, that’s 9 seconds of continuous shooting! It’s a truly impressive feat that is going to tantalize any underwater photographer looking to shoot quick subjects or owns a quick pair of strobes like the Sea & Sea YS-D3 or Ikelite DS.

The Best In-Body Image-Stabilization on the Market!

In-body image-stabilization, or IBIS, is a mechanical system built into a camera that moves the sensor to compensate for camera shake. This can allow photographers to take sharp, hand-held photos at slow shutter speeds that previously weren’t possible. IBIS has been common in full-frame mirrorless camera competitors like the Nikon Z series and Sony A7 series, but the EOS R5 and R6 are Canon’s first IBIS capable camera. When combined with an optically stabilized RF and EF lenses, the EOS R5 is capable of recovering up to 8 stops of exposure!

This is very beneficial to underwater photographers and underwater videographers alike. Underwater photographers will be able to shoot at slower shutter speeds in low light and limited visibility conditions while suffering less motion blur. Underwater videographers will be able to capture stable, handheld video in underwater environments that are notorious for their instability. Combined, with 4K @ 120fps, videographers will have the ultimate hand held underwater video system.

At the end of our dives with the R5, we realized that the IBIS offered in the Canon EOS R5 ended up being our favorite feature on the camera. When we tested the IBIS for still, we found that we were able to get amazingly crisp photos at 1/13th of a second exposures (@15mm)!! When we tested the IBIS with a 100mm macro lens in video modes, we found that the video was about as still as we had ever captured handheld. There have been some complaints about warpiness in the IBIS in video mode, but Canon seems to have fixed the issue – at least, it’s not noticeable in our underwater video.

Top-of-the-line Autofocus

Although it isn’t discussed as much as the EOS R5’s video specs, there have been some truly astounding improvements to the R5’s autofocus capability. Foremostly, the R5 is the first full-frame mirrorless camera with 100% autofocus point coverage! This means you can place an AF point anywhere on the sensor. As underwater photographers, we are often put in positions requiring awkward composition and uncentered focal points. The R5 is the ultimate compositional tool. Underwater videographers are going to be able to pair Canon’s amazing dual pixel autofocus with 100% AF coverage to capture any subject in motion.

Canon is also boasting animal eye autofocus that is better developed than it’s competitors – capable of photographing cats, birds, and dogs. We’ve tried animal eye AF with Sony and Nikon and have had mixed luck with capturing fish eyes. Overall, we’ve found Canon’s autofocus tracking system to be slightly less accurate than Sony’s but much better than Nikon’s.

When it came to animal eye autofocus tracking, we’ve been pleasantly surprised to find that when we shot macro photos, the camera was able to detect fish eyes and faces about 20-40% of the time depending on the species. When it couldn’t detect the face, the AF tracking worked anyway as long as we selected the correct AF point. In non-tracking modes, Canon’s AF is just a tad slower than Sony’s but certainly useable at a professional level in almost every photographic situation.

Canon EOS R5 for Underwater Photography

The Canon EOS R 5 is clearly one of the best tools on the market for underwater photography. A higher resolution, 45 MP sensor places the camera in the same niche as the Nikon Z7 and Sony A7R III/A7R IV. Macro photographers will appreciate the ability to shoot at a higher resolution to crop on minute details. Other working professionals will appreciate the ability to produce large prints. And with amazing burst speeds of up to 12 fps mechanical and 20 fps electronic, the EOS R5 will be an excellent camera for wide angle shooters who need to photograph quick, moving subjects.

Canon’s first rendition of IBIS in a camera promises 7-8 stops recovered with an image stabilized lens. That’s massively exciting for cold water underwater photographers that shoot in low lighting situations. To top it all off, 100% autofocus coverage and improved dual pixel autofocus tracking will give creators the capability to produce artistic works of art with unorthodox composition.

Overall, we think this camera is the best camera on the market for underwater photography. The resolution is just the right level to capture amazing, detailed images with very little noise. The dynamic range is beautiful. IBIS is our favorite feature of the camera, allowing us to take crisp underwater photos even at 1/13th of a second! The autofocus speed and autofocus tracking rarely failed us in our underwater test.

Any photographer looking to by the top of the line mirrorless camera on the market for stills photos should be looking at the Canon EOS R5. If you want the highest resolution possible, then the Sony A7R IV might be a better option. But if you want an all around great camera, with a high quality selection of lenses, we like the Canon EOS R5.

Canon EOS R5 for Underwater Video

8K video is a big deal. A really big deal. The Canon EOS R5 is the first consumer level camera to offer 8K – not to mention 8K RAW 4:2:2 10-bit! It’s going to be a gamechanger for underwater videographers. On the other hand, underwater video is going to be limited by overheating and most videographers will not have any need for 8K video. 8K will prove most useful when it is downsampled to 4K or cropped in post processing to be used as additional B roll.

What might be even more exciting than 8K video is the R5’s ability to capture 4K @ 120p and 60p using the full width of the sensor. Finally – no crop factor in a Canon mirrorless camera! It’s what underwater videographers have waiting years for. Higher frame rates allow underwater videographers to slow down their footage and stabilize the inherent motion that comes from filming underwater. The 4K video will be oversampled which means it will have more detail than normal 4K video and the lack of a crop factor will allow videographers to take full advantage of their lenses.

We think that Canon nailed the R5 as a video camera, but they failed at the marketing. They should have presented it for what it is – an amazing stills camera that can capture some spectacular video. If you want to capture spectacular video for most use cases, then shooting 4K @ 60p will allow you to avoid overheating as well as capture some beautiful video. We think that this is still one of the best cameras on the market for underwater video, but videographers will need to be willing to only use special features like 8K or 4K @120p during special, short situations.

Who Should Consider Purchasing the Canon EOS R5?

The Canon EOS R5 is one of those rare cameras that would work perfectly for any professional underwater photographer or videographer. It features in-body image-stabilization and resolutions high enough for avid macro photographers. It has burst shooting abilities good enough for wide angle shooters. The video is excellent and has the potential to revolutionize underwater video. We think any underwater creative in 2020 should consider purchasing the EOS R5 unless they are a serious video shooter that needs long run times over 20 minutes before overheating.

Lens Options for Underwater Photography

Because the RF lens mount is so new, there are a couple of RF lenses that could be viable for both wide angle and macro photography in the future (e.g., Canon RF 15-35mm f/2.8L for wide and RF 35mm f/1.8 IS Macro for semi-macro and portraits) – but nothing quite as good as the available EF and EF-S lenses with the EF-EOS R adapter.

Recommended Underwater Lenses with the EF-EOS R adapter

Macro

Macro lenses enable to you get close up shots of little critters.

Canon EF-S 60mm f/2.8 Macro: This is a great all-around macro lens. It is easier to use than the 100mm macro lens and focuses quicker. However, it has less working distance than the 100mm so it is more difficult to get shots of skittish subjects. This is the recommended lens for blackwater diving.

Canon EF 100mm f/2.8L Macro IS: This is the best macro lens for small and shy subjects due to a larger working distance. It’s also an essential tool for supermacro photography when combined with a macro diopter. We tested this lens with the Canon EOS R and loved how sharp the photos were and the working distance for skittish subjects. If you are new to macro photography, it would be better to start with the 60mm macro for faster autofocus speeds.

Nauticam Super Macro Converter: The Nauticam super macro converter (SMC-1) is a wet diopter that can help capture sharp macro and super macro images. It’s the strongest, sharpest diopter on the market. If you are a super macro photographer, this diopter is best used with the Canon 100 mm f/2.8 macro.

Wide Angle Fisheye

Wide angle fisheye lenses allow for an ultra-wide field of view but result in a distorted image. The distortion is reduced underwater to the angle of refraction of light through the water.

Canon 8-15mm f/4L circular fisheye: This is going to be the best choice for a full-frame fisheye lens. At 8mm, the lens vignettes over itself creating a cool, artistic, circular fisheye effect. For traditional fisheye images, just zoom in to 15mm and you will capture beautiful ultra-wide angle shots without vignetting. We tested this lens with the Canon EOS R and loved its functionality and quick autofocus with autofocus tracking.

Rectilinear Wide Angle

Rectilinear wide angle lenses retain a wide field of view but do not exhibit the distortion found on fisheye lenses. They are great for large animals like sharks and reefscapes.

Canon 16-35 f/2.8 III Ultra-Wide Zoom lens: This lens is the best choice for those who are buying their first wide-angle lens and don’t have a strict budget. Most underwater shooters use rectilinear wide-angle lenses for shooting subjects that don’t come close enough to fill the frame with a wide fisheye lens: sharks, whales, sea lions, dolphins, etc.

Canon 16-35mm f/2.8L II Wide-Angle Lens: This has been the most popular rectilinear wide-angle lens for Canon full frame. This lens sat at the top of the selection for the last few years in terms of corner sharpness, speed, and price… although that will change as more new shooters purchase the version III.

Canon 11-24mm f/4L Ultra Wide-Angle Lens: Want the widest lens you can buy? The Canon 11-24mm offers a much wider field of view than the 16mm. This perspective is great for reefscapes, massive wrecks, and very wide shots where you do not want the distortion of a fisheye lens. The downside is that this lens is larger, heavier and more expensive than the other wide-angle lens choices.

Underwater Housings for the Canon EOS R5

Due to the popularity of the Canon EOS R5, we anticipate underwater housings from all leading underwater housing manufactures (except those that specialize in smaller, compact cameras). It’s still a little early in the game but there are already some amazing housing options on the books from Ikelite, Aquatica, and Nauticam. Isotta and Sea & Sea will also be making housing for the EOS R5 in the coming months.

Ikelite’s housing is a nice, affordable, light-weight polycarbonate model whereas all other major brands of housing are anodized aluminum. Isotta housings have a characteristic red finish and compact form factor, Nauticam housings are compatible with Nauticam’s famous optics, Aquatica’s housings are some of the most rugged on the market, and Sea & Sea’s housings are elegantly engineered in Japan.

Currently, none of these housings will also fit the Canon EOS R6.

Conclusion

After months of drooling over the thought of shooting the Canon EOS R5, the last few dives that we had with the camera feel like an extension of our dream. The R5 rocks. It’s great. We love it. It is definitely the camera of 2020. If you are looking for an amazing high resolution stills camera with quick burst shooting, accurate AF tracking with high AF speeds, the best IBIS on the market, dual card slots, great dynamic range, minimal noise, and all-around spectacular video then you’ve found your camera.

After multiple dives with the R5, the content we captured given the conditions we had was nothing short of a miracle. This camera allows you to perceive the world and interact with your environment in ways that weren’t capable with other cameras. The IBIS lets you conquer darker depths and turbulent waters. The autofocus tracking puts you on friendly terms with the most anxious of fish. The burst rates allow you to capture the split seconds between life and death or everything in between.

Yes, Canon did a poor job in marketing the EOS R5’s video capability. But that shouldn’t hinder anyone from reading between the lines and seeing the R5 for what it truly is – the best all-around content creation tool you could take underwater.

About the Author

Nirupam Nigam is head of marketing at Bluewater Photo and the editor-in-chief of the Underwater Photography Guide. He is an avid underwater photographer, formally trained in fisheries science and biology. You can read more of his camera reviews here and here. This article was also published here and shared with permission.