Canon EOS R3vs Pentax K-3 Mark IIIvs A7 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
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
VS
Sony A7 III Sony A7 III (2018) From £1699 Best for All-round photography & video View A7 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.

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.

All-Round Photography & Video — A7 III (2018): Still one of the best all-round cameras money can buy — particularly strong used. The A7 III proved that full-frame doesn't have to mean compromises, and nothing at this price point has meaningfully beaten it.

↓ 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

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

A7 III (2018)

  • Enthusiast photographers upgrading from APS-C for the first time
  • Working photographers who need reliable AF and weather sealing
  • Anyone who shoots in low light regularly
  • Hybrid shooters needing both stills and video performance

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

Full specifications

Specification Canon EOS R3 (2021)Pentax K-3 Mark III (2021)A7 III (2018)
Price £5,999 £1,699 £1,699
Sensor 24.1MP full-frame BSI stacked CMOS 25.7MP APS-C BSI CMOS (AA-filterless) 24.2MP Full-Frame Exmor R BSI CMOS
Resolution 24.1MP 25.7MP 24.2MP
Video 6K RAW, 4K/120p, 1080p/180p 4K/30p, 1080p/60p 4K/30p (6K oversampled), 1080p/120p slow-motion
Autofocus Dual Pixel CMOS AF II with Eye Control AF SAFOX 13 phase-detect, 101-point (25 cross-type) Phase-detect, 693 points, real-time Eye AF & animal AF
Stabilisation 8-stop IBIS 5.5-stop 5-axis IBIS (Shake Reduction III) 5-axis IBIS, 5 stops
Burst Rate 30fps electronic / 12fps mechanical 12fps 10fps with AF/AE tracking
Battery Life 620 shots (CIPA) 800 shots (CIPA) ~710 shots (CIPA)
Weight 1015g body only 820g body only 565g (body, battery, card)
Dimensions 150.0 × 142.6 × 87.2mm 134.5 × 103.5 × 73.5mm 126.9 × 95.6 × 73.7mm
Weather Sealed Yes Yes Yes
Viewfinder 0.76" OLED EVF, 5.76M dots, 120fps Optical pentaprism, 100% coverage, 1.05× magnification EVF, 2.36M dots, 0.78× magnification
Screen 3.2" fully articulating touchscreen 3.2" tilting touchscreen 3.0" tilting touchscreen, 921k dots
Mount Canon RF Pentax KF-mount Sony E-mount
Memory Cards Dual CFexpress Type B Dual SD UHS-II Dual SD (UHS-II slot 1, UHS-I slot 2)
Connectivity USB-C 3.2, HDMI full-size, Wi-Fi 6, Bluetooth, LAN USB-C, Wi-Fi, Bluetooth USB-C (USB 3.2), Wi-Fi, Bluetooth, NFC
⚡ Compare specs side by side Canon EOS R3 prices → Pentax K-3 Mark III prices → A7 III prices →

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