Canon EOS R3vs OM-5vs Pentax K-3 Mark III

GearFrame · Updated March 2026

Canon Canon EOS R3 Canon Canon EOS R3 (2021) From £5999 Best for Sports & photojournalism professionals View Canon EOS R3
VS
OM System OM-5 OM System OM-5 (2022) From £899 Best for Outdoor & adventure View OM-5
VS
Pentax Pentax K-3 Mark III Pentax Pentax K-3 Mark III (2021) From £1699 Best for DSLR enthusiasts & outdoor photographers View Pentax K-3 Mark III

Which should you buy?

Sports & Photojournalism Professionals — Canon EOS R3 (2021): The pinnacle of Canon's mirrorless lineup for speed — Eye Control AF and 30fps burst in the most rugged body Canon has ever produced.

Outdoor & Adventure — OM-5 (2022): The toughest camera at this price — IP53 weather sealing and 7.5-stop IBIS built for adventure photographers.

Dslr Enthusiasts & Outdoor Photographers — Pentax K-3 Mark III (2021): The finest APS-C DSLR ever made — class-leading weather sealing, optical viewfinder, 5-axis IBIS, and extraordinary build for photographers committed to DSLR.

↓ Full specifications below

Canon EOS R3 (2021)

  • You shoot sport, motorsport, wildlife, or news at a professional level
  • You need Canon's most reliable and fastest autofocus available
  • You need extreme weather sealing for demanding shooting conditions

OM-5 (2022)

  • You need weather sealing and in-body stabilisation in a compact, lightweight body
  • You hike, travel, or shoot outdoors and want serious protection without the weight penalty
  • You're in the MFT ecosystem and want a step up in capability from entry-level bodies

Pentax K-3 Mark III (2021)

  • You're a committed DSLR photographer with significant investment in Pentax glass
  • You shoot in extreme weather conditions and place build quality and reliability above everything
  • You prefer optical viewfinder performance and want the best modern APS-C DSLR available

Quick take: The pentax k-3 mark iii has the highest resolution at 26mp; the om-5 is the most affordable. Scroll down for the full spec breakdown.

Full specifications

Specification Canon EOS R3 (2021)OM-5 (2022)Pentax K-3 Mark III (2021)
Price £5,999 £899 £1,699
Sensor 24.1MP full-frame BSI stacked CMOS 20.4MP Micro Four Thirds Live MOS 25.7MP APS-C BSI CMOS (AA-filterless)
Resolution 24.1MP 20.4MP 25.7MP
Video 6K RAW, 4K/120p, 1080p/180p 4K/60p, 4K/120p Cinema4K 4K/30p, 1080p/60p
Autofocus Dual Pixel CMOS AF II with Eye Control AF Phase-detect, 121 all-cross points, subject tracking SAFOX 13 phase-detect, 101-point (25 cross-type)
Stabilisation 8-stop IBIS 5-axis IBIS, 7.5 stops (Dual IS with compatible lenses) 5.5-stop 5-axis IBIS (Shake Reduction III)
Burst Rate 30fps electronic / 12fps mechanical 30fps electronic, 10fps mechanical 12fps
Battery Life 620 shots (CIPA) ~370 shots (CIPA) 800 shots (CIPA)
Weight 1015g body only 414g body only 820g body only
Dimensions 150.0 × 142.6 × 87.2mm 122.3 × 87.6 × 49.7mm 134.5 × 103.5 × 73.5mm
Weather Sealed Yes Yes Yes
Viewfinder 0.76" OLED EVF, 5.76M dots, 120fps EVF, 2.36M dots, 0.74× magnification Optical pentaprism, 100% coverage, 1.05× magnification
Screen 3.2" fully articulating touchscreen 3.0" fully articulating touchscreen 3.2" tilting touchscreen
Mount Canon RF Micro Four Thirds Pentax KF-mount
Memory Cards Dual CFexpress Type B Dual SD UHS-II slots Dual SD UHS-II
Connectivity USB-C 3.2, HDMI full-size, Wi-Fi 6, Bluetooth, LAN USB-C, Bluetooth, Wi-Fi USB-C, Wi-Fi, Bluetooth
⚡ Compare specs side by side Canon EOS R3 prices → OM-5 prices → Pentax K-3 Mark III prices →

Compare pairs from this group