Decision tools · Compare
OM-5 Mark II vs A7S
Quick take: The OM-5 Mark II has the highest resolution at 20MP; the A7S 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.
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Verdictwhich should you buy?
A7S — Astrophotography & Low-Light: The original A7S pioneered the concept of a camera optimised entirely for low light. Its 12.2MP sensor has enormous photosites — extraordinary high-ISO performance that still holds up. Lacking IBIS and limited to 1080p internally (4K requires external recorder), it is a specialist tool. For astrophotography, event videography, or any scenario where light is genuinely scarce, it remains outstanding.
Who should buy what
A7S (2014)
is the right camera for you if…
- Astrophotographers
- Low-light event videographers
- Filmmakers needing clean high-ISO footage
Full specificationsthe better value in each row is highlighted
| Specification | OM-5 Mark IIOM System · 2025 | A7SSony · 2014 |
|---|---|---|
| Price | £880 | £600Best |
| Sensor | 20.4MP Four Thirds Live MOS | 12.2MP Full-Frame BSI CMOS |
| Resolution | 20.4MPBest | 12.2MP |
| Video | 4K/30p, OM-Log400 | 1080p/60p internal, 4K via HDMI (external recorder) |
| Autofocus | Phase-hybrid AF (121 cross-type points) | Contrast-detect AF, 25 points |
| Stabilisation | Up to 7.5-stop Sync IS (6.5-stop body-only) | No stabilisation |
| Burst Rate | 10fps (AF tracking), 30fps (locked)Best | 5fps |
| Battery Life | 310 shots (CIPA) | ~370 shots (CIPA)Best |
| Weight | 370g (body only)Best | 474g (with battery and card) |
| Dimensions | — | 126.9 × 94.4 × 48.2mm |
| Weather Sealed | Yes | Yes |
| Viewfinder | EVF, 2.36M dots, 1.37x magnification | Electronic, 2.36M dots, 0.71× magnification |
| Screen | Fully articulating touchscreen | 3.0" tilting LCD, 1.23M dots |
| Mount | Micro Four Thirds | Sony FE (full-frame E-mount) |
| Memory Cards | Single SD (UHS-II) | Single SD / MemoryStick PRO Duo slot |
| Connectivity | USB-C, Wi-Fi, Bluetooth | Multi/Micro USB, Wi-Fi, NFC |
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-5 Mark II
A7S
Portrait
6.5/10
5.3/10
Street
6.9/10
5.7/10
Travel
6.9/10
5.8/10
Wedding & Events
5.4/10
4.3/10
Vlogging & Video
6.5/10
—
Filmmaking
5.1/10
5.9/10
Documentary
6.3/10
5.6/10
Sports & Action
6.7/10
4.8/10
Landscape
6.0/10
5.0/10
Wildlife
7.4/10
5.4/10
Casual
6.1/10
3.6/10
Food
6.9/10
4.9/10
Macro
8.1/10
4.3/10
Architecture
6.0/10
4.7/10
Astrophotography
5.5/10
6.0/10
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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