OM System OM-1 Mark IIvs A7S III
OM System
OM System OM-1 Mark II (2024)
From £1999
Best for Wildlife, birds & outdoor sports
View OM System OM-1 Mark II
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.
Professional Video & Low-Light Filmmaking — A7S III (2020): If video is your primary discipline, the A7S III is the camera. 4K/120p at 10-bit in a weather-sealed body with a 9.44M dot EVF is an extraordinary package. The 12MP sensor isn't limiting for video — and it's usable at ISO 409,600 in a pinch.
Who should buy what
OM System OM-1 Mark II (2024)
- You shoot wildlife, birds in flight, or fast-moving action where tracking accuracy is critical
- You need extreme weather sealing for shooting in rain, dust, mud, or freezing cold
- You're invested in the MFT ecosystem and want the absolute best body available
A7S III (2020)
- Filmmakers and videographers who need 4K/120p at 10-bit
- Event videographers who shoot in dark venues regularly
- Documentary filmmakers who need reliable AF and weather sealing
- Hybrid shooters where video is primary and stills are secondary
Quick take: The om system om-1 mark ii has the highest resolution at 20mp; the om system om-1 mark ii is the most affordable. Scroll down for the full spec breakdown.
Full specifications
| Specification | OM System OM-1 Mark II (2024) | A7S III (2020) |
|---|---|---|
| Price | £1,999 | £2,999 |
| Sensor | 20MP Micro Four Thirds Live MOS | 12.1MP Full-Frame BSI CMOS (12-bit, back-illuminated) |
| Resolution | 20.0MP | 12.1MP |
| Video | 4K/60p, 1080p/240p, 4K HLG | 4K/120p 10-bit, 4K/60p 10-bit S-Cinetone/S-Log3, 1080p/240p |
| Autofocus | AI subject detection AF (birds, animals, motorsport) | Phase-detect, 759 points, real-time Eye AF (human & animal), subject recognition |
| Stabilisation | 8.5-stop IBIS | 5.5-stop IBIS |
| Burst Rate | 120fps with AF tracking | 10fps mechanical |
| Battery Life | 520 shots (CIPA) | ~600 shots (CIPA) / ~70min continuous 4K recording |
| Weight | 599g body only | 699g (body, battery, card) |
| Dimensions | 134.8 × 91.6 × 72.7mm | 128.9 × 96.9 × 80.8mm |
| Weather Sealed | Yes | Yes |
| Viewfinder | 0.83" OLED EVF, 5.76M dots, 120fps | OLED EVF, 9.44M dots, 0.90× magnification — best EVF Sony has made |
| Screen | 3.0" fully articulating touchscreen | 3.0" vari-angle touchscreen, 1.44M dots |
| Mount | Micro Four Thirds | Sony E-mount |
| Memory Cards | Dual SD UHS-II | Dual CFexpress Type A / SD UHS-II (both slots) |
| Connectivity | USB-C, Wi-Fi, Bluetooth | USB-C (USB 3.2 Gen 2), full-size HDMI, Wi-Fi 6, Bluetooth |
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