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Pentax K-3 Mark IIIvs A7

GearFrame · Updated March 2026

Pentax Pentax K-3 Mark III Pentax Pentax K-3 Mark III (2021) Starting from £1699 new Best for DSLR enthusiasts & outdoor photographers View Pentax K-3 Mark III
VS
Sony A7 Sony A7 (2013) Starting from £299 new Best for Camera history & full-frame introduction View A7

GearScore™ Verdict — 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.

Camera History & Full-Frame Introduction — A7 (2013): The camera that changed photography — the world's first compact full-frame mirrorless, the A7 launched a product family that redefined what was possible.

↓ Full specifications below

Pentax K-3 Mark III (2021)

  • DSLR photographers who want the finest APS-C optical viewfinder experience
  • Outdoor and weather photographers who need robust all-weather sealing
  • Pentax lens owners who want to use their existing K-mount glass
  • Photographers who prefer optical viewfinders and refuse to switch to mirrorless

A7 (2013)

  • Photographers interested in the camera that launched the full-frame mirrorless era
  • Budget-conscious buyers who want to experience full-frame image quality at minimal cost
  • Sony FE system users who want the original A7 for sentimental or historical value
  • Those adapting vintage lenses who want full-frame with phase-detect AF at low cost

Quick take: The pentax k-3 mark iii has the highest resolution at 26mp; the a7 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)A7 (2013)
Price £1,699 £299
Sensor 25.7MP APS-C BSI CMOS (AA-filterless) 24.3MP Full-Frame CMOS
Resolution 25.7MP 24.3MP
Video 4K/30p, 1080p/60p 1080p/60p
Autofocus SAFOX 13 phase-detect, 101-point (25 cross-type) 117 phase-detect + 25 contrast-detect AF points
Stabilisation 5.5-stop 5-axis IBIS (Shake Reduction III) None
Burst Rate 12fps 5fps
Battery Life 800 shots (CIPA) ~340 shots (CIPA)
Weight 820g body only 474g (with battery and card)
Dimensions 134.5 × 103.5 × 73.5mm 126.9 × 94.4 × 48.2mm
Weather Sealed Yes No
Viewfinder Optical pentaprism, 100% coverage, 1.05× magnification EVF, OLED 2.36M dots, 0.71× magnification
Screen 3.2" tilting touchscreen 3.0" fixed LCD, 1.23M dots (no tilt, no touch)
Mount Pentax KF-mount Sony FE (full-frame E-mount)
Memory Cards Dual SD UHS-II Single SD UHS-I slot
Connectivity USB-C, Wi-Fi, Bluetooth USB, Wi-Fi, NFC
Genre Pentax K-3 Mark IIIA7
Landscape
9.0
9.0
Wildlife
9.0
Sports & Action
9.0
4.0
Portrait
7.0
9.0
Travel
7.0
7.0
Vlogging & Video
4.0
4.0
Street
7.0

GearScore™ suitability scores are based on aggregated purchaser reviews weighted by photography genre. See how scores are calculated →

⚡ Compare specs side by side Pentax K-3 Mark III prices → A7 prices →

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