Decision tools · Compare
OM-1 vs A7S II
Quick take: The OM-1 has the highest resolution at 20MP; the A7S II is the most affordable.
16 specs side by side·15 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
A7S II 2015
Best for Low-light video, documentary & available-light filmmaking
£799
list price · used from £400 at eBay
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Verdictwhich should you buy?
OM-1 — Wildlife, Sport, Outdoor: OM System's statement camera — class-leading weather sealing and the best IBIS in the business.
A7S II — Low-Light Video, Documentary & Available-Light Filmmaking: A landmark in mirrorless history — the first Sony with IBIS and internal 4K, its low-light video capability still impresses today at a used-market price.
Who should buy what
OM-1 (2022)
is the right camera for you if…
- Wildlife and bird photographers who need fast burst and pro weather sealing
- Outdoor photographers who work in challenging conditions
A7S II (2015)
is the right camera for you if…
- Filmmakers and videographers who want legendary low-light performance at a used-price discount
- Documentary shooters working in unpredictable available light conditions
- A7S III shooters who want a second Sony FE body for backup or B-camera use
- Budget-conscious video producers who want full-frame 4K with S-Log at an accessible price
Full specificationsthe better value in each row is highlighted
| Specification | OM-1OM System · 2022 | A7S IISony · 2015 |
|---|---|---|
| Price | £1,299 | £799Best |
| Sensor | Micro Four Thirds Live MOS stacked BSI | 12.1MP full-frame BSI Exmor CMOS |
| Resolution | 20.4MPBest | 12.1MP |
| Video | 4K 60fps 10-bit | 4K/30p internal (full sensor readout), 1080p/120p, S-Log2/S-Log3 |
| Autofocus | 1053-point cross-type phase-detect, AI subject recognition | Contrast-detect AF, 169 points; limited by modern standards |
| Stabilisation | 5-axis IBIS, 7.0 stops (8 stops with sync IS) | 5-axis IBIS — 4.5 stops (first Sony mirrorless with IBIS) |
| Burst Rate | 10fps mechanical, 50fps electronic, 120fps Pro CaptureBest | 5fps continuous |
| Battery Life | 520 shots (CIPA)Best | ~370 shots (CIPA) |
| Weight | 599g (body only) | 584g (body only)Best |
| Dimensions | 134.8 × 91.6 × 72.7mm | 126.9 × 95.7 × 60.3mm |
| Weather Sealed | Yes | Yes |
| Viewfinder | EVF 0.83× 5.76M-dot | EVF, 2.36M dots, 0.71× magnification |
| Screen | 3.0" fully articulating touchscreen, 1.62M-dot | 3.0" tilting LCD, 1.23M dots |
| Mount | Micro Four Thirds | Sony FE mount (full-frame E-mount) |
| Memory Cards | Dual SD UHS-II slots | Dual SD UHS-I slots |
| Connectivity | Wi-Fi 5GHz, Bluetooth 5.0, USB-C 3.1, HDMI, 3.5mm mic/headphone | USB Micro-B, Bluetooth (via app), 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
OM-1
A7S II
Portrait
7.3/10
5.8/10
Street
6.5/10
5.3/10
Travel
6.2/10
5.2/10
Wedding & Events
7.6/10
5.6/10
Vlogging & Video
6.3/10
—
Filmmaking
6.6/10
6.2/10
Documentary
7.6/10
5.8/10
Sports & Action
9.2/10
5.2/10
Landscape
6.0/10
5.0/10
Wildlife
9.0/10
5.6/10
Casual
5.6/10
3.5/10
Food
7.1/10
5.2/10
Macro
8.1/10
4.8/10
Architecture
6.1/10
4.8/10
Astrophotography
5.9/10
6.8/10
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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