Pentax K-3 Mark IIIvs A9
Pentax
Pentax K-3 Mark III (2021)
Starting from £1699 new
Best for DSLR enthusiasts & outdoor photographers
View Pentax K-3 Mark III
Sony
A9 (2017)
Starting from £1999 new
Best for Professional sports, wildlife & action photography
View A9
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.
Professional Sports, Wildlife & Action Photography — A9 (2017): The camera that changed professional photography — the A9's 20fps blackout-free burst and silent shutter proved mirrorless had definitively surpassed the DSLR.
Who should buy what
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
A9 (2017)
- Sports photographers who want the original 20fps mirrorless at a lower used price than the A9 II
- Wildlife photographers who need blackout-free burst with fast, reliable tracking
- Sony FE system users who want a professional sports body
- Photographers interested in the camera that changed the industry
Quick take: The pentax k-3 mark iii has the highest resolution at 26mp; the pentax k-3 mark iii is the most affordable. Scroll down for the full spec breakdown.
Full specifications
| Specification | Pentax K-3 Mark III (2021) | A9 (2017) |
|---|---|---|
| Price | £1,699 | £1,999 |
| Sensor | 25.7MP APS-C BSI CMOS (AA-filterless) | 24.2MP Full-Frame Stacked BSI CMOS Exmor RS |
| Resolution | 25.7MP | 24.2MP |
| Video | 4K/30p, 1080p/60p | 4K/30p, 1080p/120p |
| Autofocus | SAFOX 13 phase-detect, 101-point (25 cross-type) | 693 phase-detect + 25 contrast-detect, real-time eye/body tracking |
| Stabilisation | 5.5-stop 5-axis IBIS (Shake Reduction III) | IBIS — 5-axis, up to 5 stops |
| Burst Rate | 12fps | 20fps (blackout-free, silent electronic shutter with full AF/AE) |
| Battery Life | 800 shots (CIPA) | ~650 shots (CIPA) |
| Weight | 820g body only | 673g (with battery and card) |
| Dimensions | 134.5 × 103.5 × 73.5mm | 126.9 × 95.6 × 63.0mm |
| Weather Sealed | Yes | Yes |
| Viewfinder | Optical pentaprism, 100% coverage, 1.05× magnification | EVF, OLED 3.69M dots, 0.78× magnification, 60fps refresh (blackout-free) |
| Screen | 3.2" tilting touchscreen | 3.0" tilting touchscreen |
| Mount | Pentax KF-mount | Sony FE (full-frame E-mount) |
| Memory Cards | Dual SD UHS-II | Dual SD UHS-II slots |
| Connectivity | USB-C, Wi-Fi, Bluetooth | USB, Wi-Fi 5GHz, Bluetooth, HDMI |
Suitability by genre
| Genre | Pentax K-3 Mark III | A9 |
|---|---|---|
| Landscape | — | |
| Wildlife | ||
| Sports & Action | ||
| Portrait | ||
| Travel | ||
| Vlogging & Video | ||
| Wedding & Events | — |
GearScore™ suitability scores are based on aggregated purchaser reviews weighted by photography genre. See how scores are calculated →
More comparisons with Pentax K-3 Mark III
Camera family history