Pentax K-3 Mark IIIvs A5100
Pentax
Pentax K-3 Mark III (2021)
Starting from £1699 new
Best for DSLR enthusiasts & outdoor photographers
View Pentax K-3 Mark III
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.
Casual & Travel — A5100 (2014): The A5100 is one of the smallest APS-C mirrorless cameras ever made. Its 24MP sensor, phase-detect AF, and selfie-friendly flip screen pack remarkable capability into a shirt-pocket-sized body. No EVF or hot shoe limits it for serious use, but as a compact travel camera or beginner's first mirrorless, it punches well above its price on the used market.
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
A5100 (2014)
- Beginners stepping up from a smartphone
- Compact travel photographers
- Casual vloggers who want APS-C quality
Quick take: The pentax k-3 mark iii has the highest resolution at 26mp; the a5100 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) | A5100 (2014) |
|---|---|---|
| Price | £1,699 | £200 |
| Sensor | 25.7MP APS-C BSI CMOS (AA-filterless) | 24.3MP APS-C Exmor CMOS |
| Resolution | 25.7MP | 24.3MP |
| Video | 4K/30p, 1080p/60p | 1080p/60p |
| Autofocus | SAFOX 13 phase-detect, 101-point (25 cross-type) | Hybrid phase-detect / contrast-detect AF, face detection |
| Stabilisation | 5.5-stop 5-axis IBIS (Shake Reduction III) | None |
| Burst Rate | 12fps | 6fps |
| Battery Life | 800 shots (CIPA) | ~400 shots (CIPA) |
| Weight | 820g body only | 224g (body only) |
| Dimensions | 134.5 × 103.5 × 73.5mm | 109.6 × 62.8 × 35.7mm |
| Weather Sealed | Yes | No |
| Viewfinder | Optical pentaprism, 100% coverage, 1.05× magnification | None |
| Screen | 3.2" tilting touchscreen | 3.0" flip-up touchscreen, 921k dots |
| Mount | Pentax KF-mount | Sony E-mount |
| Memory Cards | Dual SD UHS-II | Single SD / MemoryStick PRO Duo slot |
| Connectivity | USB-C, Wi-Fi, Bluetooth | Micro USB, Wi-Fi, NFC |
Suitability by genre
| Genre | Pentax K-3 Mark III | A5100 |
|---|---|---|
| Landscape | ||
| Wildlife | — | |
| Sports & Action | ||
| Portrait | ||
| Travel | ||
| Vlogging & Video | ||
| Casual | — | |
| Street | — |
GearScore™ suitability scores are based on aggregated purchaser reviews weighted by photography genre. See how scores are calculated →
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