EOS R8vs Pentax K-3 Mark IIIvs Sigma fp

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
Sigma Sigma fp Sigma Sigma fp (2019) From £1499 Best for Creative filmmakers & experimental photographers View Sigma fp

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.

Creative Filmmakers & Experimental Photographers — Sigma fp (2019): The smallest full-frame camera in the world — Cinema DNG RAW and L-mount flexibility in a pocket-sized body that rewards creative shooters.

↓ 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

Sigma fp (2019)

  • You're a filmmaker building a cinema rig where the smallest full-frame body is essential
  • You want L-mount compatibility to pair with Sigma Art or Leica SL lenses
  • You prioritise video and cinema colour over stills ergonomics and functionality

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 is weather sealed. Scroll down for the full spec breakdown.

Full specifications

Specification EOS R8 (2023)Pentax K-3 Mark III (2021)Sigma fp (2019)
Price £1,099 £1,699 £1,499
Sensor 24.2MP Full-frame BSI CMOS 25.7MP APS-C BSI CMOS (AA-filterless) 24.6MP full-frame Bayer CMOS
Resolution 24.2MP 25.7MP 24.6MP
Video 4K/60p oversampled 10-bit, FHD/180p 4K/30p, 1080p/60p 12-bit Cinema DNG RAW, 4K/24p, 1080p/120p
Autofocus Dual Pixel CMOS AF II, 1053 zones, eye/face/subject tracking SAFOX 13 phase-detect, 101-point (25 cross-type) Contrast-detect AF with face/eye detection
Stabilisation None (no IBIS) 5.5-stop 5-axis IBIS (Shake Reduction III) None (lens-based only)
Burst Rate 6fps mechanical, 40fps electronic 12fps 18fps electronic
Battery Life ~220 shots (CIPA) 800 shots (CIPA) 200 shots (CIPA)
Weight 461g body only 820g body only 422g body only
Dimensions 132.5 × 86.1 × 70.0mm 134.5 × 103.5 × 73.5mm 112.6 × 69.9 × 45.3mm
Weather Sealed No Yes No
Viewfinder EVF, 2.36M dots, 0.59× Optical pentaprism, 100% coverage, 1.05× magnification None
Screen 3.0" fully articulating touchscreen 3.2" tilting touchscreen 3.15" fixed touchscreen
Mount Canon RF mount (full-frame) Pentax KF-mount Leica L-mount
Memory Cards Single SD UHS-II slot Dual SD UHS-II Single SD UHS-II + CFexpress Type B (via adapter)
Connectivity USB-C, Bluetooth, Wi-Fi USB-C, Wi-Fi, Bluetooth USB-C 3.1, Wi-Fi, Bluetooth
⚡ Compare specs side by side EOS R8 prices → Pentax K-3 Mark III prices → Sigma fp prices →

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