EOS R8vs Pentax K-3 Mark IIIvs Sony A9 III

GearFrame · Updated March 2026

Canon EOS R8 Canon EOS R8 (2023) From £1099 Best for Full-frame entry View EOS R8
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 Sony A9 III Sony Sony A9 III (2023) From £5999 Best for Sports & action professionals View Sony A9 III

Which should you buy?

Full-Frame Entry — EOS R8 (2023): Canon's most affordable full-frame mirrorless — 4K/60p 10-bit and class-leading Dual Pixel AF at an accessible entry price.

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.

Sports & Action Professionals — Sony A9 III (2023): A paradigm-shifting camera — the global shutter eliminates every rolling shutter limitation that has constrained action photography for years.

↓ Full specifications below

EOS R8 (2023)

  • You want full-frame image quality on a tight budget
  • You shoot mainly in good light and can live without built-in stabilisation
  • You primarily shoot stills with occasional video

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

Sony A9 III (2023)

  • You shoot professional sport, motorsport, or action and need zero rolling shutter distortion
  • You need reliable high-speed flash sync for studio or on-location action work
  • You want the absolute pinnacle of Sony's action and sports camera technology

Quick take: The pentax k-3 mark iii has the highest resolution at 26mp; the eos r8 is the most affordable; only the pentax k-3 mark iii, sony a9 iii are weather sealed. Scroll down for the full spec breakdown.

Full specifications

Specification EOS R8 (2023)Pentax K-3 Mark III (2021)Sony A9 III (2023)
Price £1,099 £1,699 £5,999
Sensor 24.2MP Full-frame BSI CMOS 25.7MP APS-C BSI CMOS (AA-filterless) 24.6MP full-frame Exmor RS CMOS (global shutter)
Resolution 24.2MP 25.7MP 24.6MP
Video 4K/60p oversampled 10-bit, FHD/180p 4K/30p, 1080p/60p 4K/120p, 4K/60p, 1080p/240p
Autofocus Dual Pixel CMOS AF II, 1053 zones, eye/face/subject tracking SAFOX 13 phase-detect, 101-point (25 cross-type) AI subject recognition AF, 759-point phase-detect
Stabilisation None (no IBIS) 5.5-stop 5-axis IBIS (Shake Reduction III) 8-stop IBIS
Burst Rate 6fps mechanical, 40fps electronic 12fps 120fps blackout-free electronic
Battery Life ~220 shots (CIPA) 800 shots (CIPA) 530 shots (CIPA)
Weight 461g body only 820g body only 703g body only
Dimensions 132.5 × 86.1 × 70.0mm 134.5 × 103.5 × 73.5mm 136.1 × 96.9 × 82.9mm
Weather Sealed No Yes Yes
Viewfinder EVF, 2.36M dots, 0.59× Optical pentaprism, 100% coverage, 1.05× magnification 0.64" Quad-XGA OLED EVF, 9.44M dots
Screen 3.0" fully articulating touchscreen 3.2" tilting touchscreen 3.2" fully articulating touchscreen
Mount Canon RF mount (full-frame) Pentax KF-mount Sony FE (E-mount)
Memory Cards Single SD UHS-II slot Dual SD UHS-II Dual CFexpress Type A / SD UHS-II
Connectivity USB-C, Bluetooth, Wi-Fi USB-C, Wi-Fi, Bluetooth USB-C 3.2, HDMI A, Wi-Fi 6, Bluetooth 5.3
⚡ Compare specs side by side EOS R8 prices → Pentax K-3 Mark III prices → Sony A9 III prices →

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