EOS Mvs A7S III
Canon
EOS M (2012)
Starting from £80 new
Best for Canon mirrorless history & EF-M collectors
View EOS M
Sony
A7S III (2020)
Starting from £2999 new
Best for Professional video & low-light filmmaking
View A7S III
GearScore™ Verdict — Which should you buy?
Canon Mirrorless History & Ef-M Collectors — EOS M (2012): Canon's first mirrorless — a historic body that broke new ground with touch-AF and EF-M, but its sluggish contrast-detect system quickly became its Achilles heel.
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
EOS M (2012)
- Canon shooters who want the camera that started Canon's mirrorless story
- Budget first-time mirrorless buyers who already own EF/EF-S glass
- Collectors of significant digital camera milestones
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 eos m has the highest resolution at 18mp; the eos m is the most affordable; only the a7s iii is weather sealed. Scroll down for the full spec breakdown.
Full specifications
| Specification | EOS M (2012) | A7S III (2020) |
|---|---|---|
| Price | £80 | £2,999 |
| Sensor | 18MP APS-C CMOS | 12.1MP Full-Frame BSI CMOS (12-bit, back-illuminated) |
| Resolution | 18.0MP | 12.1MP |
| Video | 1080p 30fps | 4K/120p 10-bit, 4K/60p 10-bit S-Cinetone/S-Log3, 1080p/240p |
| Autofocus | Contrast-detect AF only — notoriously slow | Phase-detect, 759 points, real-time Eye AF (human & animal), subject recognition |
| Stabilisation | — | 5.5-stop IBIS |
| Burst Rate | 4fps | 10fps mechanical |
| Battery Life | ~230 shots (CIPA) | ~600 shots (CIPA) / ~70min continuous 4K recording |
| Weight | 262g (body only) | 699g (body, battery, card) |
| Dimensions | 108.6 × 66.5 × 32.3mm | 128.9 × 96.9 × 80.8mm |
| Weather Sealed | No | Yes |
| Viewfinder | None (optional EVF accessory) | OLED EVF, 9.44M dots, 0.90× magnification — best EVF Sony has made |
| Screen | 3.0" fixed touchscreen, 1.04M dots | 3.0" vari-angle touchscreen, 1.44M dots |
| Mount | Canon EF-M mount | Sony E-mount |
| Memory Cards | 1× SD/SDHC/SDXC | Dual CFexpress Type A / SD UHS-II (both slots) |
| Connectivity | USB 2.0 | USB-C (USB 3.2 Gen 2), full-size HDMI, Wi-Fi 6, Bluetooth |
Suitability by genre
| Genre | EOS M | A7S III |
|---|---|---|
| Casual | — | |
| Travel | ||
| Street | ||
| Portrait | ||
| Vlogging & Video | — | |
| Video | — | |
| Wildlife | — |
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