Upgrade Guide
Sony A7R III→Sony A5100
Is it worth upgrading? Spec analysis, key improvements, and our verdict.
→
Skip it
The A5100 offers little measurable spec improvement over the A7R III. Spend the money on glass instead.
Unchanged or similar
-
Resolution24MP (down from 42MP — optimised for low light)
-
Weather sealingNot present in new body
-
StabilisationIBIS not present in new body
Suitability by genre
| Genre | A7R III | A5100 | |
|---|---|---|---|
| Landscape | -2.5 | ||
| Portrait | -1.5 | ||
| Vlogging & Video | — | ||
| Wedding | — | ||
| Street | +0.5 | ||
| Sports | — | ||
| Casual | — | ||
| Travel | — | ||
| Sports & Action | — |
Full spec comparison
| Spec | A7R III | A5100 | |
|---|---|---|---|
| Price | £1,799 | £200 | |
| Released | 2017 | 2014 | ↓ |
| Sensor | 42.4MP full-frame BSI Exmor R CMOS | 24.3MP APS-C Exmor CMOS | |
| Resolution | 42MP | 24MP | ↓ |
| Video | 4K/30p (full-frame readout), 1080p/120p | 1080p/60p | |
| Autofocus | 399 phase-detect + 425 contrast AF points — real-time Eye AF | Hybrid phase-detect / contrast-detect AF, face detection | |
| Stabilisation | 5-axis IBIS — 5.5 stops | None | |
| Burst Rate | 10fps with AF/AE tracking | 6fps | ↓ |
| Battery Life | ~650 shots (CIPA) | ~400 shots (CIPA) | ↓ |
| Weight | 650g body only | 224g (body only) | ↑ |
| Weather Sealed | Yes | No | ↓ |
| Viewfinder | EVF, 3.69M dots, 0.78× magnification | None | |
| Screen | 3.0" touchscreen, tilting | 3.0" flip-up touchscreen, 921k dots | |
| Mount | Sony FE mount (full-frame E-mount) | Sony E-mount | |
| Memory Cards | Dual SD slots (one UHS-II) | Single SD / MemoryStick PRO Duo slot |
Compare side-by-side
⚖️ Compare these cameras
See A7R III and A5100 next to each other with our interactive comparison tool.
Get a personalised upgrade score
Run the upgrade checker →
Tell us what you shoot and we'll score the A5100 against your specific genres — not just specs.
Other upgrades from the A7R III
Related buying guides
Camera family history