Canon EOS R

Manufacturer: Canon
Type: camera (full-frame mirrorless)
Sensor: 30.3MP full-frame CMOS
Processor: DIGIC 8
Mount: Canon RF (54mm diameter, 20mm flange distance)
Year introduced: 2018 (announced September 5; available October 2018)
Launch price: $2,299 (body only); $3,399 (with RF 24-105mm f/4 L IS USM kit)
ISO range: 100-40,000 (expandable to 102,400)
Continuous shooting: 8.0 fps
Video: 4K UHD up to 30fps; 10-bit 4:2:2 external via HDMI; Canon Log (12 stops DR)
EVF: 3.69 million dots
Card slot: Single UHS-II SD
Battery life: ~350 shots (CIPA)
Key feature: Canon’s first full-frame mirrorless camera; Dual Pixel CMOS AF with 5,655 selectable AF points; RF mount with full EF/EF-S lens compatibility via adapters

Overview

The Canon EOS R was Canon’s first full-frame mirrorless camera, formally announced on September 5, 2018, as the debut of the new RF mount system. It represented Canon’s response to the Sony mirrorless juggernaut, arriving alongside Nikon’s Z6/Z7 as DSLR manufacturers transitioned toward mirrorless designs. Canon positioned it as “the next revolution in the company’s long history of innovative and award-winning camera systems” (^[1]).

The EOS R featured a 30.3-megapixel CMOS sensor powered by a DIGIC 8 image processor, enabling continuous shooting at up to 8.0 fps. Its Dual Pixel CMOS AF system offered 5,655 manually selectable AF points, supporting autofocus at up to f/11 with a 384-zone (24x16) real-time metering system. With f/1.2 RF lenses, AF sensitivity extended down to an exceptional -6 EV in low light. Using the RF 24-105mm f/4 L IS USM lens, Canon claimed focus acquisition in as little as 0.05 seconds, which it described as “the fastest autofocus speed in the world” among full-frame mirrorless cameras with phase-detection AF at the time of announcement (^[2]).

The camera recorded 4K UHD video at up to 30fps with 10-bit 4:2:2 output to an external recorder via HDMI. It included Canon Log for 12 stops of dynamic range, inheriting capabilities from Canon’s Cinema EOS line. Canon U.S.A. President Kazuto Ogawa stated: “The EOS R system is not just a new camera or a new lens mount, it is a new design that will allow us to produce visual tools that were previously impossible” (^[3]). However, community members noted that the 4K video mode applied a significant crop, making wide-angle video shooting impractical (^[4]).

Additional features included a built-in EVF with 3.69 million dots, a vari-angle touchscreen LCD, a dot-matrix LCD panel, a silent shutter mode for single-shot shooting (with a planned free firmware update to enable silent shutter in continuous shooting mode), CR3/C-RAW and Dual Pixel RAW support, dust and weather resistance, USB 3.1 in-camera charging, built-in Bluetooth and Wi-Fi, and a single UHS-II SD card slot. Canon also introduced a new Multi-Function Bar placed just to the right of the EVF for customizable access to settings such as AF, ISO, and white balance, allowing users to “slide or tap the bar to gain access to the settings” (^[5]).

Canon simultaneously announced Digital Photo Professional Express (DPP Express), enabling users to send, view, edit, and process CR3 RAW files on iPads via the Canon Camera Connect App (^[6]).

The EOS R shared the same 30.3MP sensor as the Canon 5D Mark IV, offering familiar image quality to Canon full-frame DSLR shooters in a more compact mirrorless body (^[7]).

RF Mount and Lens Compatibility

The RF mount was the most strategically significant aspect of the EOS R for underwater photographers. Sharing the same 54mm diameter as the legacy EF mount but with a shorter back-focus distance, the RF mount allowed lenses to sit closer to the sensor, enabling “larger rear lens elements to produce an image on the full-frame sensor” with “increased corner and outer edge sharpness.” A 12-pin high-speed communication system provided “faster and more in-depth communication between the camera and lens over existing Canon mount systems” (^[8], ^[9]).

Canon launched four initial RF lenses alongside the EOS R: the RF 28-70mm f/2 L USM, RF 50mm f/1.2 L USM, RF 24-105mm f/4 L IS USM, and RF 35mm f/1.8 Macro IS STM. RF lenses featured a customizable control ring that could be assigned to control various exposure settings, and manual focus was controlled electronically, allowing the direction of rotation to be configured via camera menu (^[10], ^[11]).

Full backward compatibility with all existing EF, EF-S, TS-E, and MP-E lenses was provided through three mount adapter options: a simple EF-to-R adapter, one with a customizable control ring for additional camera controls (such as ISO adjustment), and one with a drop-in filter mount supporting variable ND filters. When using EF-S lenses, the camera automatically switched to APS-C crop mode (^[12], ^[13]).

This backward compatibility was particularly important for underwater photographers, as it meant Canon shooters could transition to mirrorless without abandoning their proven EF lens investments. Community members confirmed that the Canon 8-15mm fisheye zoom lens worked well with the EOS R via adapter, and this combination was highlighted as delivering the best results by reviewer Phil Rudin in UwP magazine (^[14]).

However, the RF mount’s large 54mm diameter meant that Sony E-mount lenses (46.1mm) could not be adapted to it, unlike the reverse. This limited wet wide-angle lens options: Nauticam did not list any Canon full-frame lenses as compatible with their WWL-1 wet lens, unlike the Sony 28-60mm (^[15]).

Underwater Considerations

Strengths

Canon’s white balance performance was praised by community members as significantly better than Sony, an important consideration for ambient light and video shooting underwater (^[16]).

The camera’s 4K UHD video output with 10-bit 4:2:2 to an external recorder made it compatible with the Atomos Ninja V monitor/recorder, joining the Panasonic GH5 and GH5S as cameras that could take “full advantage of the Ninja V 4k 10-bit 422 recording to Apple ProRes or Avid DNxHR” (^[17]).

Limitations

The most commonly discussed limitation was the absence of in-body image stabilization (IBIS). While Wetpixel editor Adam Hanlon and multiple community members noted that IBIS is generally not essential for underwater still photography — since water buoyancy acts as a “semi-tripod” and strobes freeze motion — it was acknowledged as useful for underwater video. Canon historically relied on lens-based IS rather than in-body stabilization, lagging behind Olympus, Panasonic, and Sony in this regard (^[18]).

Adam Hanlon also noted that “the AF on the new full frame Sony cameras seems to be significantly better than that of the EOS R,” suggesting AF performance was not class-leading among mirrorless cameras (^[19]).

Battery life was rated at only 350 shots, worse than many competing cameras including the Olympus E-M1 Mark II (440 shots), which concerned some divers who disliked changing batteries on dive boats (^[20]).

Custom white balance required a cumbersome multi-step process on the EOS R that could not be saved, reducing the advantage of Canon’s superior white balance in practice (^[21]).

The 4K video crop made wide-angle video impractical, limiting the camera’s dual-purpose appeal (^[22]).

Housing Availability

Housing manufacturers responded rapidly to the EOS R, with all major housings shipping within approximately three months of the camera’s October 2018 availability. All major housings supported both RF-mount lenses and EF-mount lenses via Canon’s adapters, with port systems designed for backward compatibility with existing Canon DSLR port configurations.

Ikelite 200DL

Ikelite announced their 200DL housing in November 2018 for mid-November shipping. Constructed of their signature lightweight, corrosion-free ABS-PC blend, the housing was depth-rated to 60m (200 feet). It featured the DL port system supporting RF-mount and EF-mount lenses, a pre-installed vacuum valve, a spare M16 port for HDMI bulkheads or third-party accessories, and a manual hotshoe with ICS-5 bulkhead. The shutter and AF-ON controls used “super sensitive and natural feeling curved levers,” and all push-button controls were “machined and hard anodized aluminum to reduce weight and resist salt build-up.” The back of the housing was laser-engraved with control symbols “which will never fade or fall off.” The camera mount was front-loading with a mounting plate that did not need to be removed for surface use, battery changes, or tripod mounting (^[23]).

TTL exposure was available via the optional CT2K Canon TTL Kit with compatible DS strobes, supporting rear curtain synchronization and in-camera exposure compensation. In February 2020, Ikelite shipped the DL5 DS Canon TTL Converter, a new external TTL system compatible with Canon SLR and mirrorless cameras including the EOS R, priced at $375-$400 depending on kit configuration (^[24]).

Nimar M-PRO

Nimar shipped their M-PRO housing in November 2018, making it one of the earliest available housings for the EOS R. Part of their new M-PRO line dedicated to mirrorless cameras, it was constructed of acetal resin and aluminum alloy, depth-rated to 100m (328 feet), and priced at EUR 1,490. The housing used the NIM-108M port system, featured an integrated synchro flash trigger with dual fiber-optic direct plug-in, both manual and optional electronic vacuum systems, a moisture alarm, luminescent buttons, snap-locking latches, and ergonomic aluminum handle brackets with 1-inch ball mounts. Dimensions were 350mm x 170mm x 150mm at 2.3 kg. The housing came with a soft bag backpack, spare main seal, silicon grease, silica gel, test certificate, and USB card with tutorial videos (^[25]).

A user comment from February 2020 noted that the Nimar housing for the EOS R appeared to have been discontinued: “Looking forward to getting this but apparently they are discontinued. I may have gotten the last one for the EOS R” (^[26]). At least one Wetpixel community member (Diarmuid) was shopping for the Nimar M-PRO housing as a budget alternative to Nauticam or Subal, though other forum members encountered issues with dual strobe triggering on some Nimar configurations (^[27]).

Nauticam NA-R

Nauticam shipped their NA-R housing in December 2018, priced at $3,300. It used the N120 port system, providing full compatibility with existing Nauticam Canon DSLR port configurations — “existing Nauticam DSLR housing owners can easily share lens port accessories with the new NA-R housing.” The large-diameter N120 port mount was specifically chosen to support both legacy EF-mount DSLR configurations and accommodate incoming RF-mount lenses (^[28]).

The housing featured two lens release buttons (one for RF lenses, one for EF lenses with adapter), optional manual or TTL flash triggers using built-in fiber-optic bulkheads, HDMI output support, and a vacuum bulkhead (M16 Vacuum Valve II) as standard. Depth-rated to 100m, it weighed 3.06 kg with dimensions of 360mm x 200mm x 160mm (^[29]).

The NA-R’s control layout embodied Nauticam’s “Mission Control” philosophy: a dual thumb lever and dual sub-lever by the right handle (AF-ON, Info, M-Fn, and Record buttons), a playback lever near the left handle, and a dedicated EVF/LCD switch. Large knurled and rubberized control dials accessed the camera’s main and sub command dials. A two-stage trigger allowed for “smooth focus and firing activation.” An optional gear (PN 19561) allowed control of the Canon EF-EOS R Control Ring Mount Adapter from the housing (^[30]).

At the BOOT 2019 show in Dusseldorf, Nauticam demonstrated the NA-R housing, highlighting its design philosophy of integrating the Canon lens adapter into the body to maintain compatibility with existing ports, extensions, and zoom gears. Nauticam also demonstrated controls and gearing for all three Canon adapter variants, including the control ring and drop-in filter mount adapters (^[31]).

Sea&Sea MDX-R

Sea&Sea announced their MDX-R housing in December 2018. Described as a “state-of-the-art housing for the full-frame mirrorless Canon EOS R camera,” it was “compact, compatible with the Optical YS Converter and ergonomically designed.” Compatible with existing MDX series ports and gears, the housing featured dual focus/zoom gears — one dedicated for RF mount lenses and one for EF mount lenses. It weighed 2,900g on land, 100g lighter than the MDX-5D Mark IV housing (^[32]).

The MDX-R included a port lock system with a lever “specifically located to avoid being unlocked accidentally,” a lens-lock release button for lens changes without opening the housing, a pull-out focus/zoom dial to accommodate larger-diameter lenses, luminescence stickers on all controls, a standard 0.5x optical viewfinder (with optional 0.66x and 0.8x viewfinders), a 2-pin sync cord connector for manual hard-wired strobe firing, two sacrificial zinc diodes for electrolysis protection, a viewing window for the camera’s upper control panel (with “greatly improved” visibility due to the camera’s brighter display), and an under guard for scratch protection (^[33]).

Easydive LeoR

In October 2021, Easydive shipped their LeoR universal camera housing, compatible with the EOS R among many other mirrorless and DSLR cameras. Priced at EUR 3,490, it offered camera control via USB, WiFi, IR, or Bluetooth, an integrated OLED display, dual SDI output, and two external battery packs. The Android App-configurable system represented a different approach from traditional mechanical housings (^[34]).

Related RF Mount Accessories

• Sea&Sea YS Optical Converter C/R: Shipped April 2019, this converter enabled TTL and manual exposure control with YS-D1 and YS-D2 strobes when the EOS R was housed in the MDX-R. Controlled via a button on the housing, it converted the camera’s hot-shoe TTL signal into an LED light signal for fiber-optic strobe triggering (^[35]).

• Canon RF fisheye zoom lens patent: In March 2019, Canon Rumors discovered that Canon had registered a patent with the US Patent and Trademark Office for an 8-15mm RF-mount fisheye zoom lens. The patent described versions for both APS-C (5.30-9.51mm, f/3.5, 181-182 degree angle of view) and full-frame (8.01-15.30mm, f/3.78-4.60, 177-183 degree angle of view) use, with a back focus shorter than the EF version’s 44mm. No release date or pricing was announced (^[36]).

• Ikelite DL5 DS Canon TTL Converter: Shipped February 2020, compatible with Canon mirrorless cameras including the EOS R in Ikelite 200DL housings (^[37]).

Reviews and Coverage

Phil Rudin reviewed the Canon EOS R in the Ikelite 200DL housing for Underwater Photography (UwP) magazine Issue 106 (January/February 2019). He reported the best results were achieved with the Canon 8-15mm fisheye zoom using the Canon lens adapter. By 2021, Rudin noted that “Canon has made great strides in both camera features and RF native lenses since my early 2019 review,” pointing to the EOS R5, R6, and RF 100mm f/2.8L macro as examples of the platform’s maturation (^[38], ^[39]).

UwP magazine Issue 110 (September/October 2019) also featured EOS R content (^[40]).

In February 2022, Alex Mustard and Adam Hanlon discussed the EOS R series on Wetpixel Live, reviewing camera options for underwater image-makers including the R5, R6, Nikon Z9, Sony a1, and OM Digital OM-1 (^[41]).

Community Discussion

The EOS R generated extensive discussion on the Wetpixel forums about Canon’s mirrorless transition and its implications for underwater photographers.

• IBIS debate (12 replies, 2019): A detailed thread explored whether the lack of IBIS was a dealbreaker. Adam Hanlon stated IBIS “is not really useful for underwater use” since water buoyancy enables slower handheld shutter speeds. Community member interceptor121 noted IBIS was useful for underwater video but not stills. Multiple members debated EOS R vs. Olympus E-M1 II vs. Sony options, with considerations including dome size, system cost, and battery life (^[42]).

• EOS R experience thread (5 replies, 2021): Users discussed whether to choose Canon SLR or mirrorless. Community consensus favored going mirrorless given Canon’s discontinuation of EF lenses. Experienced user timg cautioned that “the newest technology is not necessarily the best underwater” and emphasized lens availability over body features (^[43]).

• Full-frame ambient light comparison (29 replies, 2020): The EOS R was compared against the Sony A7III, Nikon Z6, and Canon 5D Mark IV for freediving and ambient light shooting. Canon’s superior white balance was repeatedly cited, but the cumbersome custom WB process on the EOS R was flagged as a significant drawback (^[44]).

• Full-frame camera poll (39 replies, 2019): In Adam Hanlon’s survey of preferred full-frame cameras, the Nikon D850 dominated responses, with the EOS R receiving less attention than established DSLRs. This reflected the early stage of the mirrorless transition in the underwater photography community (^[45]).

• Mirrorless AF comparison (35 replies, 2021): The EOS R was discussed alongside the R5 and R6 for macro AF performance using Canon’s 100mm macro lens via adapter and the new RF 85mm macro (^[46]).

• WWL-1 compatibility (72 replies, 2021): A thread on using Nauticam’s WWL-1 wet wide-angle lens with Canon full-frame cameras revealed a significant gap: no Canon RF or EF lens was listed as compatible with the WWL-1, unlike Sony’s compact 28-60mm lens. The large RF mount diameter (54mm vs. Sony’s 46.1mm) made it unlikely that Canon would produce a lens small enough to work with the WWL system (^[47]).

• DSLR APS-C phase-out impact (2019): Community discussion about the broader impact of DSLR phase-out on underwater photography, with the EOS R system cited as evidence of Canon’s strategic direction (^[48]).

• RF 14-35mm f/4 L lens (2021): Forum members discussed the new RF 14-35mm f/4 L lens for underwater wide-angle use with the R-series system (^[49]).

Legacy and Successors

The EOS R served as the foundation for Canon’s RF mount ecosystem, which expanded rapidly:

• 2019-02: Canon announced the EOS RP, a more affordable entry-level full-frame mirrorless at $1,299 with a 26.2MP sensor, positioned as a step-up from APS-C cameras (^[50]).
• 2020-07: Canon announced the Canon EOS R5 and Canon EOS R6, which added IBIS, dramatically improved video (8K on R5), and advanced AF systems, addressing the original EOS R’s key limitations (^[51]).
• 2021-04: Canon announced the RF 100mm f/2.8 L Macro IS USM with 1.4x maximum magnification, a key lens for underwater macro photography (^[52]).
• 2021-06: Canon announced the RF 14-35mm f/4 L IS USM ultra-wide zoom (^[53]).
• 2021-09: Canon announced the EOS R3, a professional sports/wildlife body (^[54]).
• 2021-09: Canon announced the RF 16mm f/2.8 STM pancake lens (^[55]).
• 2022-06: Canon expanded the RF system to APS-C with the EOS R7 and R10, both sharing the R3’s AF system and featuring IBIS (^[56]).
• 2022-11: Canon announced the EOS R6 Mark II (^[57]).
• 2023-02: Canon announced the EOS R8 and R50 (^[58]).

By 2021, Canon had discontinued a large number of EF lenses, signaling the permanent shift to the RF mount that the EOS R had inaugurated (^[59]).

Timeline

• 2018-09-05: Canon announces the EOS R System with RF mount and four initial RF lenses at $2,299 body-only, available October 2018 (^[60]).
• 2018-11-05: Ikelite announces 200DL housing for mid-November shipping (^[61]).
• 2018-11-06: Nimar ships M-PRO housing at EUR 1,490, depth-rated to 100m (^[62]).
• 2018-12-04: Nauticam ships NA-R housing at $3,300, depth-rated to 100m, with N120 port system (^[63]).
• 2018-12-22: Sea&Sea announces MDX-R housing with dual focus/zoom gears, 100g lighter than MDX-5D Mark IV (^[64]).
• 2019-01: Nauticam demonstrates NA-R housing at BOOT 2019 in Dusseldorf, showing adapter integration and control ring gearing (^[65]).
• 2019-01: Phil Rudin reviews EOS R in Ikelite 200DL housing for UwP magazine Issue 106, reporting best results with Canon 8-15mm fisheye via adapter (^[66]).
• 2019-02: Canon announces EOS RP, second RF-mount camera at $1,299 (^[67]).
• 2019-03: Canon patents RF-mount 8-15mm fisheye zoom lens with both APS-C and full-frame embodiments (^[68]).
• 2019-04: Sea&Sea ships YS Optical Converter C/R for TTL strobe control (^[69]).
• 2019-09: UwP magazine Issue 110 features EOS R content (^[70]).
• 2020-02: Ikelite ships DL5 DS Canon TTL Converter compatible with EOS R (^[71]).
• 2020-02: Nimar housing for EOS R reported as discontinued (^[72]).
• 2020-07: Canon announces EOS R5 and R6 with IBIS, addressing EOS R’s key limitation (^[73]).
• 2021-04: Canon announces RF 100mm f/2.8 L Macro IS USM (^[74]).
• 2021-10: Easydive ships LeoR universal housing compatible with EOS R at EUR 3,490 (^[75]).
• 2022-02: Alex Mustard and Adam Hanlon discuss EOS R series on Wetpixel Live (^[76]).