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Canon

EOS-1D X Mark III

Canon flagship DSLR for sports and news with 20fps and legendary reliability.

$6,499

Released Feb 2020

vs

Canon

EOS R3

Pro 24MP full-frame stacked-sensor body built for sports, news, wildlife, and high-speed hybrid capture.

$5,999

Released Sep 2021

EOS R3 is 1.6 years newer.

Wins

4categories

EOS-1D X Mark III

WildlifeSports & Action

Wins

7categories

EOS R3

Video & HybridPortrait

7 categories tied

TL;DR — Key differences

EOS-1D X Mark III wins 1 categories·EOS R3 wins 4 categories
  • BEOS R3 has higher Max video bit rate (2600 Mbps vs 150 Mbps)
  • BEOS R3 has higher AF points / zones (1053 vs 191)
  • BEOS R3 has higher 4K max frame rate (120 fps vs 60 fps)
  • BEOS R3 has higher Burst (electronic) (30 fps vs 20 fps)
  • AEOS-1D X Mark III has lower Weight (720 g vs 1015 g)

Key specs at a glance

EOS-1D X Mark IIIEOS R3
Resolution20.1 MP24.1 MP
SensorFull FrameFull Frame
ISO max102,400102,400
Burst20 fps30 fps
4K60 fps120 fps
IBIS8-stop8-stop
Weight720 g1015 g
Battery520 shots620 shots

Size and weight, to scale

EOS-1D X Mark III

138 × 98 × 88 mm

720 g (1.59 lb / 25.40 oz)

EOS R3

150 × 143 × 87 mm

1015 g (2.24 lb / 35.80 oz)

EOS-1D X Mark III is 12mm narrower and 45mm shorter than EOS R3 but it is also 1mm thicker.

EOS-1D X Mark III is 295 g lighter than EOS R3.

Depth (front-to-back): 88mm EOS-1D X Mark III · 87mm EOS R3

Sensor size, to scale

EOS-1D X Mark III

36 × 24 mm · Full Frame

864 mm² area

EOS R3

36 × 24 mm · Full Frame

864 mm² area

Lens ecosystem

Native lens selection

EOS-1D X Mark III

✓ more lenses

Canon EF

300+

native lenses available

100 first-party200 third-party

EOS R3

Canon RF

105+

native lenses available

45 first-party60 third-party

Counts include current first-party and major third-party native autofocus lenses.

Use-case scoring

Which one for what?

Algorithmic scores from verified specs · 10 = best in class

Use caseEOS-1D X Mark IIIEOS R3
Portrait
6.5Good
7.5Good✓ wins
Sports & Action
7.0Good
7.0Good
Video & Hybrid
6.0Good
9.0Excellent✓ wins
Landscape
5.5Fair
7.0Good✓ wins
Travel
6.0Good
6.5Good✓ wins
Wildlife
10.0Excellent✓ wins
5.0Fair
Vlogging
5.5Fair
5.5Fair

Why pick one over the other

Reasons to choose

EOS-1D X Mark III

  • Subject recognition

    Adds Human, Animal, Bird…

  • Dimensions (W×H×D mm)

    Adds 138, 98, 88

  • Pre-Capture / Pre-Release

    Only EOS-1D X Mark III supports it

  • Weight

    720 g vs 1015 g — lower is better

  • Burst (mechanical)

    16 fps vs 12 fps — higher is better

  • RAW buffer depth

    200 frames vs 150 frames — higher is better

  • EVF magnification

    0.78 × vs 0.76 × — higher is better

Reasons to choose

EOS R3

  • AF low-light limit

    -7.5 EV vs -4 EV — lower is better

  • Subject recognition

    Adds People, Dogs, Cats…

  • Dimensions (W×H×D mm)

    Adds 150, 142.6, 87.2

  • Max video bit rate

    2600 Mbps vs 150 Mbps — higher is better

  • AF points / zones

    1053 vs 191 — higher is better

  • Animal / bird AF

    Only EOS R3 supports it

  • 4K max frame rate

    120 fps vs 60 fps — higher is better

  • Burst (electronic)

    30 fps vs 20 fps — higher is better

Both cameras share

  • AA filterBoth support aa filter
  • ISO min (native)Both 100
  • ISO max (native)Both 102,400
  • AF frame coverageBoth 100 %
  • Eye AFBoth support eye af
  • Internal RAW videoBoth support internal raw video

Pros & cons at a glance

Editorially curated highlights and trade-offs.

EOS-1D X Mark III

Pros

  • 20fps DSLR
  • Pro build
  • Dual CFexpress
  • Excellent AF

Cons

  • DSLR platform
  • 20MP
  • Very heavy

EOS R3

Pros

  • 30fps electronic burst from a stacked full-frame sensor
  • Exceptional low-light AF down to -7.5 EV
  • Integrated pro body with large LP-E19 battery
  • 6K RAW video and 4K 120p
  • Rugged weather-sealed construction

Cons

  • 24MP resolution trails higher-detail rivals
  • Large integrated-grip body
  • Expensive compared with enthusiast full-frame bodies

Full specifications

= category winner

EOS-1D X Mark III
EOS R3
Resolution
20.1 MP
24.1 MP+20%
Sensor type
Full Frame CMOS
Full Frame Stacked BSI CMOS
Sensor size
36.0 × 24.0 mm
36.0 × 24.0 mm
AA filter
Yes
Yes
EOS-1D X Mark III
EOS R3
AF system
191-point phase-detect AF / Dual Pixel CMOS AF
Dual Pixel CMOS AF II
AF points / zones
191
10535.5× more
AF frame coverage
100 %
100 %
AF low-light limit
-4 EV
-7.5 EV
Eye AF
Yes
Yes
Animal / bird AF
No
Yes
Subject recognition
Human, Animal, Bird, Vehicle
People, Dogs, Cats, Birds, Motorsport vehicles
EOS-1D X Mark III
EOS R3
Burst (mechanical)
16 fps+33%
12 fps
Burst (electronic)
20 fps
30 fps+50%
Pre-Capture / Pre-Release
Yes
No
RAW buffer depth
200 frames+33%
150 frames
EOS-1D X Mark III
EOS R3
Max resolution
5.5K RAW
6K RAW
4K max frame rate
60 fps
120 fps2× more
Max video bit rate
150 Mbps
2600 Mbps17.3× more
Internal RAW video
Yes
Yes
Log profile
Canon Log
Canon Log 3 / HDR PQ
Codecs
RAW, H.265, H.264
RAW, H.265, H.264
EOS-1D X Mark III
EOS R3
Weight
720 g−295 g less
1015 g
Dimensions (W×H×D mm)
138 × 98 × 88 mm
150 × 142.6 × 87.2 mm
Weather sealing
Yes
Yes

Frequently asked

Quick answers generated from verified specs.

Which is better for wildlife, EOS-1D X Mark III or EOS R3?

EOS-1D X Mark III scores 10.0/10 versus 5.0/10 for EOS R3 — 20fps burst captures fleeting moments.

What's the resolution difference between the EOS-1D X Mark III and EOS R3?

EOS-1D X Mark III is 20.1 MP and EOS R3 is 24.1 MP, so the EOS R3 captures more detail for cropping and large prints.

Do the EOS-1D X Mark III and EOS R3 have in-body image stabilization?

EOS-1D X Mark III has 8-stop in-body image stabilization, while eOS R3 has 8-stop in-body image stabilization.

Which shoots faster bursts — the EOS-1D X Mark III or the EOS R3?

EOS-1D X Mark III reaches 20 fps electronic. EOS R3 reaches 30 fps electronic.

What's the weight difference between the EOS-1D X Mark III and EOS R3?

EOS-1D X Mark III weighs 720 g and EOS R3 weighs 1015 g, so the EOS-1D X Mark III is 295 g lighter.

Do the EOS-1D X Mark III and EOS R3 record 4K video?

EOS-1D X Mark III: 4K up to 60p. EOS R3: 6K RAW (max), 4K up to 120p.

Are the EOS-1D X Mark III and EOS R3 weather sealed?

EOS-1D X Mark III: Yes. EOS R3: Yes.

Which has better battery life?

Rated battery life is 520 shots (CIPA) for the EOS-1D X Mark III and 620 shots for the EOS R3, giving the EOS R3 the edge.

How much does each cost?

EOS-1D X Mark III launched at $6,499 and EOS R3 at $5,999. The EOS R3 is $500 less.

Specs sourced from manufacturer data. Use-case scores algorithmically derived. Last reviewed May 2026.