Decision tools · Compare
A5100 vs A7R III
Quick take: The A7R III has the highest resolution at 42MP; the A5100 is the most affordable; only the A7R III is weather sealed.
16 specs side by side·16 genres scored·UK prices from Wex Photo Video and Clifton Cameras
How to read this page. Highlighted cells win that row on the spec alone. Genre scores are the engine's base scores (enthusiast, photo and video); Camera Match re-weights them for your level and priorities. Price buttons are affiliate links; the price you pay is the same.
Sony
A7R III 2017
Best for Landscape, studio & commercial photography
£704
used today at Wex Photo Video
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Verdictwhich should you buy?
A5100 — Casual & Travel: 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.
A7R III — Landscape, Studio & Commercial Photography: The camera that converted professionals to mirrorless — 42MP, IBIS, and 10fps in a body that still competes today.
Who should buy what
A5100 (2014)
is the right camera for you if…
- Beginners stepping up from a smartphone
- Compact travel photographers
- Casual vloggers who want APS-C quality
A7R III (2017)
is the right camera for you if…
- Landscape and studio photographers who need 42MP resolution at a used-price discount vs A7R IV
- Canon/Nikon DSLR professionals considering a mirrorless switch at a lower investment
- Commercial and product photographers who want full-frame resolution with IBIS for handheld work
- Portrait photographers who want the sharpest possible full-frame files for large print work
Full specificationsthe better value in each row is highlighted
| Specification | A5100Sony · 2014 | A7R IIISony · 2017 |
|---|---|---|
| Price | £102 usedBest | £704 used |
| Sensor | 24.3MP APS-C Exmor CMOS | 42.4MP full-frame BSI Exmor R CMOS |
| Resolution | 24.3MP | 42.4MPBest |
| Video | 1080p/60p | 4K/30p (full-frame readout), 1080p/120p |
| Autofocus | Hybrid phase-detect / contrast-detect AF, face detection | 399 phase-detect + 425 contrast AF points — real-time Eye AF |
| Stabilisation | No stabilisation | 5-axis IBIS — 5.5 stops |
| Burst Rate | 6fps | 10fps with AF/AE trackingBest |
| Battery Life | ~400 shots (CIPA) | ~650 shots (CIPA)Best |
| Weight | 224g (body only)Best | 650g (body only) |
| Dimensions | 109.6 × 62.8 × 35.7mm | 126.9 × 95.6 × 73.7mm |
| Weather Sealed | Not weather sealed | YesBest |
| Viewfinder | No viewfinder | EVF, 3.69M dots, 0.78× magnification |
| Screen | 3.0" flip-up touchscreen, 921k dots | 3.0" touchscreen, tilting |
| Mount | Sony E-mount | Sony FE mount (full-frame E-mount) |
| Memory Cards | Single SD / MemoryStick PRO Duo slot | Dual SD slots (one UHS-II) |
| Connectivity | Micro USB, Wi-Fi, NFC | USB-C, Bluetooth, Wi-Fi, 3.5mm mic jack |
Wins the row — price, resolution, burst, battery, weight and sealing are compared; text specs aren't ranked.
How they score by genreengine base scores out of 10
Genre
A5100
A7R III
Portrait
5.4/10
7.8/10
Street
7.0/10
6.1/10
Travel
6.4/10
6.1/10
Wedding & Events
3.5/10
7.5/10
Vlogging & Video
4.7/10
—
Documentary
4.1/10
6.7/10
Sports & Action
4.7/10
7.3/10
Landscape
5.0/10
7.4/10
Wildlife
5.5/10
7.6/10
Casual
5.2/10
4.7/10
Food
5.9/10
7.0/10
Macro
5.2/10
6.2/10
Architecture
5.2/10
7.5/10
Astrophotography
4.7/10
7.0/10
Fun & simple
4.9/10
—
Filmmaking
—
6.3/10
Scores come from the same engine as Camera Match: verified specifications weighted by what each genre needs, with documented adjustments. The product page and this table show the enthusiast base score. See how scores are calculated →
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