Pentax K-3 Mark IIIvs A7C

GearFrame · Updated March 2026

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 A7C Sony A7C (2020) From £1299 Best for Compact travel & content creation View A7C

Which should you buy?

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.

Compact Travel & Content Creation — A7C (2020): The A7C proves full-frame doesn't have to be bulky. Excellent battery life, reliable Eye AF and a vari-angle screen in a pocketable body is a compelling combination for travel and content creators. The A7C II improved on it, but the original remains a strong value buy.

↓ Full specifications below

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

A7C (2020)

  • Travel photographers who want full-frame in the smallest possible body
  • Content creators who need a flip screen and reliable Eye AF
  • Photographers upgrading from APS-C who want to keep a compact kit
  • Vloggers who need 4K and great battery life on the road

Quick take: The pentax k-3 mark iii has the highest resolution at 26mp; the a7c is the most affordable; only the pentax k-3 mark iii is weather sealed. Scroll down for the full spec breakdown.

Full specifications

Specification Pentax K-3 Mark III (2021)A7C (2020)
Price £1,699 £1,299
Sensor 25.7MP APS-C BSI CMOS (AA-filterless) 24.2MP Full-Frame Exmor R BSI CMOS
Resolution 25.7MP 24.2MP
Video 4K/30p, 1080p/60p 4K/30p (oversampled), 1080p/120p slow-motion, S-Log2/S-Log3
Autofocus SAFOX 13 phase-detect, 101-point (25 cross-type) Phase-detect, 693 points, real-time Eye AF & animal AF
Stabilisation 5.5-stop 5-axis IBIS (Shake Reduction III) 5-axis IBIS, 5 stops
Burst Rate 12fps 10fps with AF/AE tracking
Battery Life 800 shots (CIPA) ~740 shots (CIPA) — outstanding for a Sony mirrorless
Weight 820g body only 509g (body, battery, card)
Dimensions 134.5 × 103.5 × 73.5mm 124.0 × 71.1 × 59.7mm
Weather Sealed Yes No
Viewfinder Optical pentaprism, 100% coverage, 1.05× magnification None built-in — use rear screen or accessory EVF
Screen 3.2" tilting touchscreen 3.0" vari-angle touchscreen, 921k dots
Mount Pentax KF-mount Sony E-mount
Memory Cards Dual SD UHS-II Single SD UHS-II
Connectivity USB-C, Wi-Fi, Bluetooth USB-C (USB 3.2 Gen 2), Wi-Fi, Bluetooth, NFC
⚡ Compare specs side by side Pentax K-3 Mark III prices → A7C prices →

More comparisons with Pentax K-3 Mark III