EOS R100vs Canon EOS R3vs Pentax K-3 Mark III

GearFrame · Updated March 2026

Canon EOS R100 Canon EOS R100 (2023) From £529 Best for First camera / beginner photography View EOS R100
VS
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

Which should you buy?

First Camera / Beginner Photography — EOS R100 (2023): The R100 does the basics well at the lowest possible price point. Its main value is as a gateway into the Canon RF ecosystem — the lenses you buy now will work on any Canon body you upgrade to later. Modest ambitions, reliably met.

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.

↓ Full specifications below

EOS R100 (2023)

  • First-time camera buyers stepping up from a smartphone
  • Students and hobbyists wanting an affordable starting point
  • Anyone who wants to start investing in Canon RF glass on a budget
  • Casual photographers who don't need advanced video or speed

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

Quick take: The pentax k-3 mark iii has the highest resolution at 26mp; the eos r100 is the most affordable; only the canon eos r3, pentax k-3 mark iii are weather sealed. Scroll down for the full spec breakdown.

Full specifications

Specification EOS R100 (2023)Canon EOS R3 (2021)Pentax K-3 Mark III (2021)
Price £529 £5,999 £1,699
Sensor 24.1MP APS-C CMOS 24.1MP full-frame BSI stacked CMOS 25.7MP APS-C BSI CMOS (AA-filterless)
Resolution 24.1MP 24.1MP 25.7MP
Video 4K/30p (slight crop), 1080p/60p 6K RAW, 4K/120p, 1080p/180p 4K/30p, 1080p/60p
Autofocus Dual Pixel CMOS AF, face detection, subject tracking Dual Pixel CMOS AF II with Eye Control AF SAFOX 13 phase-detect, 101-point (25 cross-type)
Stabilisation None (no IBIS) 8-stop IBIS 5.5-stop 5-axis IBIS (Shake Reduction III)
Burst Rate 6.5fps mechanical 30fps electronic / 12fps mechanical 12fps
Battery Life ~270 shots (CIPA) 620 shots (CIPA) 800 shots (CIPA)
Weight 356g (body, battery, card) 1015g body only 820g body only
Dimensions 116.3 × 85.5 × 68.8mm 150.0 × 142.6 × 87.2mm 134.5 × 103.5 × 73.5mm
Weather Sealed No Yes Yes
Viewfinder EVF, 2.36M dots, 0.59× magnification 0.76" OLED EVF, 5.76M dots, 120fps Optical pentaprism, 100% coverage, 1.05× magnification
Screen 3.0" fixed touchscreen, 1.04M dots 3.2" fully articulating touchscreen 3.2" tilting touchscreen
Mount Canon RF-mount Canon RF Pentax KF-mount
Memory Cards Single SD UHS-II Dual CFexpress Type B Dual SD UHS-II
Connectivity USB-C, Wi-Fi, Bluetooth USB-C 3.2, HDMI full-size, Wi-Fi 6, Bluetooth, LAN USB-C, Wi-Fi, Bluetooth
⚡ Compare specs side by side EOS R100 prices → Canon EOS R3 prices → Pentax K-3 Mark III prices →

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