Canon EOS R3vs Canon EOS R5 Mark IIvs 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
Canon Canon EOS R5 Mark II Canon Canon EOS R5 Mark II (2024) From £4299 Best for Hybrid shooters & professionals View Canon EOS R5 Mark II
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.

Hybrid Shooters & Professionals — Canon EOS R5 Mark II (2024): The most complete hybrid camera Canon has ever made — 45MP stacked BSI, 30fps burst, 8K/60p RAW, and Canon's legendary Dual Pixel AF in one body.

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

Canon EOS R5 Mark II (2024)

  • You're a working photographer or filmmaker who needs high-resolution stills and professional video
  • You shoot commercial, editorial, or high-end portrait work
  • You want the absolute best Canon mirrorless has to offer

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 canon eos r5 mark ii has the highest resolution at 45mp; the pentax k-3 mark iii is the most affordable. Scroll down for the full spec breakdown.

Full specifications

Specification Canon EOS R3 (2021)Canon EOS R5 Mark II (2024)Pentax K-3 Mark III (2021)
Price £5,999 £4,299 £1,699
Sensor 24.1MP full-frame BSI stacked CMOS 45MP full-frame BSI stacked CMOS 25.7MP APS-C BSI CMOS (AA-filterless)
Resolution 24.1MP 45.0MP 25.7MP
Video 6K RAW, 4K/120p, 1080p/180p 8K/60p RAW, 4K/120p, Cinema RAW Light 4K/30p, 1080p/60p
Autofocus Dual Pixel CMOS AF II with Eye Control AF Dual Pixel CMOS AF II, AI subject tracking SAFOX 13 phase-detect, 101-point (25 cross-type)
Stabilisation 8-stop IBIS 8-stop IBIS (coordinated with IS lenses) 5.5-stop 5-axis IBIS (Shake Reduction III)
Burst Rate 30fps electronic / 12fps mechanical 30fps electronic / 12fps mechanical 12fps
Battery Life 620 shots (CIPA) 570 shots (CIPA) 800 shots (CIPA)
Weight 1015g body only 746g body only 820g body only
Dimensions 150.0 × 142.6 × 87.2mm 138.5 × 101.2 × 93.5mm 134.5 × 103.5 × 73.5mm
Weather Sealed Yes Yes Yes
Viewfinder 0.76" OLED EVF, 5.76M dots, 120fps 0.64" OLED EVF, 5.76M dots, 120fps Optical pentaprism, 100% coverage, 1.05× magnification
Screen 3.2" fully articulating touchscreen 3.2" fully articulating touchscreen 3.2" tilting touchscreen
Mount Canon RF Canon RF Pentax KF-mount
Memory Cards Dual CFexpress Type B CFexpress Type B + SD UHS-II Dual SD UHS-II
Connectivity USB-C 3.2, HDMI full-size, Wi-Fi 6, Bluetooth, LAN USB-C 3.2, HDMI full-size, Wi-Fi 6, Bluetooth USB-C, Wi-Fi, Bluetooth
⚡ Compare specs side by side Canon EOS R3 prices → Canon EOS R5 Mark II prices → Pentax K-3 Mark III prices →

Compare pairs from this group