Pentax K-3 Mark IIIvs A6400
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?
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.
Content Creation & Vlogging — A6400 (2019): The best value APS-C Sony you can buy — especially used. Real-time Eye AF at this price point was transformative when it launched and still makes it one of the most reliable autofocus systems in the lineup.
Who should buy what
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
A6400 (2019)
- Vloggers and content creators who need a flip screen and reliable AF
- Photographers upgrading from a compact or smartphone
- Beginners who want room to grow into a full E-mount lens ecosystem
- Anyone prioritising autofocus performance at an accessible price
Quick take: The pentax k-3 mark iii has the highest resolution at 26mp; the a6400 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) | A6400 (2019) |
|---|---|---|
| Price | £1,699 | £899 |
| Sensor | 25.7MP APS-C BSI CMOS (AA-filterless) | 24.2MP APS-C Exmor CMOS BSI |
| Resolution | 25.7MP | 24.2MP |
| Video | 4K/30p, 1080p/60p | 4K/30p (6K oversampled, no crop), 1080p/120p slow-motion |
| Autofocus | SAFOX 13 phase-detect, 101-point (25 cross-type) | Phase-detect, 425 points, real-time Eye AF & animal AF |
| Stabilisation | 5.5-stop 5-axis IBIS (Shake Reduction III) | None (no IBIS) |
| Burst Rate | 12fps | 11fps mechanical, 8fps with AF tracking |
| Battery Life | 800 shots (CIPA) | ~410 shots (CIPA) |
| Weight | 820g body only | 403g (body, battery, card) |
| Dimensions | 134.5 × 103.5 × 73.5mm | 120.0 × 66.9 × 59.7mm |
| Weather Sealed | Yes | No |
| Viewfinder | Optical pentaprism, 100% coverage, 1.05× magnification | EVF, 2.36M dots, 0.70× magnification |
| Screen | 3.2" tilting touchscreen | 3.0" tilting touchscreen, 180° flip for selfie/vlog, 921k dots |
| Mount | Pentax KF-mount | Sony E-mount |
| Memory Cards | Dual SD UHS-II | Single SD UHS-I |
| Connectivity | USB-C, Wi-Fi, Bluetooth | Micro-USB, Wi-Fi, Bluetooth, NFC |
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