OM-3vs A7
OM System
OM-3 (2024)
Starting from £999 new
Best for Travel, outdoor & adventure photography
View OM-3
GearScore™ Verdict — Which should you buy?
Travel, Outdoor & Adventure Photography — OM-3 (2024): The ideal mid-range OM System camera — weather sealed, class-leading IBIS, and superb computational features in a compact body.
Camera History & Full-Frame Introduction — A7 (2013): The camera that changed photography — the world's first compact full-frame mirrorless, the A7 launched a product family that redefined what was possible.
Who should buy what
OM-3 (2024)
- Outdoor and adventure photographers who need weather sealing and compact size
- Wildlife and bird photographers wanting improved AF over the OM-5
- Travel shooters who want a rugged, lightweight MFT system
- OM-5 or E-M5 III owners wanting better autofocus without going to the OM-1
A7 (2013)
- Photographers interested in the camera that launched the full-frame mirrorless era
- Budget-conscious buyers who want to experience full-frame image quality at minimal cost
- Sony FE system users who want the original A7 for sentimental or historical value
- Those adapting vintage lenses who want full-frame with phase-detect AF at low cost
Quick take: The a7 has the highest resolution at 24mp; the a7 is the most affordable; only the om-3 is weather sealed. Scroll down for the full spec breakdown.
Full specifications
| Specification | OM-3 (2024) | A7 (2013) |
|---|---|---|
| Price | £999 | £299 |
| Sensor | 20.4MP Live MOS Micro Four Thirds | 24.3MP Full-Frame CMOS |
| Resolution | 20.4MP | 24.3MP |
| Video | 4K/60p (10-bit), C4K/30p, 1080p/120p | 1080p/60p |
| Autofocus | Phase-detect AF — subject recognition (human, animal, bird, vehicle) | 117 phase-detect + 25 contrast-detect AF points |
| Stabilisation | IBIS — up to 6.5 stops (7.5 stops with Sync IS lenses) | None |
| Burst Rate | 10fps mechanical, 30fps electronic with AF | 5fps |
| Battery Life | ~400 shots (CIPA) | ~340 shots (CIPA) |
| Weight | 414g (with battery) | 474g (with battery and card) |
| Dimensions | 122.3 × 84.6 × 49.4mm | 126.9 × 94.4 × 48.2mm |
| Weather Sealed | Yes | No |
| Viewfinder | EVF, 2.36M dots, 0.74× magnification | EVF, OLED 2.36M dots, 0.71× magnification |
| Screen | 3.0" fully articulating touchscreen | 3.0" fixed LCD, 1.23M dots (no tilt, no touch) |
| Mount | Micro Four Thirds | Sony FE (full-frame E-mount) |
| Memory Cards | Single SD UHS-II slot | Single SD UHS-I slot |
| Connectivity | USB-C, Wi-Fi, Bluetooth | USB, Wi-Fi, NFC |
Suitability by genre
| Genre | OM-3 | A7 |
|---|---|---|
| Travel | ||
| Wildlife | — | |
| Landscape | ||
| Street | ||
| Portrait | ||
| Vlogging & Video | ||
| Sports & Action | — |
GearScore™ suitability scores are based on aggregated purchaser reviews weighted by photography genre. See how scores are calculated →
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Camera family history