OM System OM-1 Mark IIvs A5100
OM System
OM System OM-1 Mark II (2024)
Starting from £1999 new
Best for Wildlife, birds & outdoor sports
View OM System OM-1 Mark II
GearScore™ Verdict — Which should you buy?
Wildlife, Birds & Outdoor Sports — OM System OM-1 Mark II (2024): OM System's most capable camera — 120fps AF burst, AI subject detection, and IP53 weather sealing make it the best-value pro wildlife camera.
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
OM System OM-1 Mark II (2024)
- Wildlife and bird photographers who need the best subject tracking in MFT
- Sports photographers who want weather sealing and 50fps burst
- OM-1 owners looking for a meaningful autofocus upgrade
- Professionals who need pro-grade weather sealing in the lightest possible system
A5100 (2014)
- Beginners stepping up from a smartphone
- Compact travel photographers
- Casual vloggers who want APS-C quality
Quick take: The a5100 has the highest resolution at 24mp; the a5100 is the most affordable; only the om system om-1 mark ii is weather sealed. Scroll down for the full spec breakdown.
Full specifications
| Specification | OM System OM-1 Mark II (2024) | A5100 (2014) |
|---|---|---|
| Price | £1,999 | £200 |
| Sensor | 20MP Micro Four Thirds Live MOS | 24.3MP APS-C Exmor CMOS |
| Resolution | 20.0MP | 24.3MP |
| Video | 4K/60p, 1080p/240p, 4K HLG | 1080p/60p |
| Autofocus | AI subject detection AF (birds, animals, motorsport) | Hybrid phase-detect / contrast-detect AF, face detection |
| Stabilisation | 8.5-stop IBIS | None |
| Burst Rate | 120fps with AF tracking | 6fps |
| Battery Life | 520 shots (CIPA) | ~400 shots (CIPA) |
| Weight | 599g body only | 224g (body only) |
| Dimensions | 134.8 × 91.6 × 72.7mm | 109.6 × 62.8 × 35.7mm |
| Weather Sealed | Yes | No |
| Viewfinder | 0.83" OLED EVF, 5.76M dots, 120fps | None |
| Screen | 3.0" fully articulating touchscreen | 3.0" flip-up touchscreen, 921k dots |
| Mount | Micro Four Thirds | 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 | OM System OM-1 Mark II | A5100 |
|---|---|---|
| Wildlife | — | |
| Sports & Action | ||
| Landscape | ||
| Travel | ||
| Portrait | ||
| 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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Camera family history