A7S IIIvs FX3
Sony
A7S III (2020)
Starting from £2999 new
Best for Professional video & low-light filmmaking
View A7S III
Sony
FX3 (2021)
Starting from £3799 new
Best for Professional video, documentary & cinematic filmmaking
View FX3
GearScore™ Verdict — Which should you buy?
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.
Professional Video, Documentary & Cinematic Filmmaking — FX3 (2021): The definitive run-and-gun cinema camera — A7S III sensor quality in a body built specifically for video professionals.
Who should buy what
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
FX3 (2021)
- Professional videographers and filmmakers who need cinema-quality colour science in a compact body
- Documentary and run-and-gun shooters who need 4K/120p and built-in XLR audio
- Sony A7S III owners who want a purpose-built video body alongside their stills camera
- Gimbal and drone operators who need a compact full-frame cinema camera
Quick take: The a7s iii is the most affordable. Scroll down for the full spec breakdown.
Full specifications
| Specification | A7S III (2020) | FX3 (2021) |
|---|---|---|
| Price | £2,999 | £3,799 |
| Sensor | 12.1MP Full-Frame BSI CMOS (12-bit, back-illuminated) | 12.1MP full-frame BSI Exmor R CMOS (same as A7S III) |
| Resolution | 12.1MP | 12.1MP |
| Video | 4K/120p 10-bit, 4K/60p 10-bit S-Cinetone/S-Log3, 1080p/240p | 4K/120p, 4K/60p 10-bit, 12-bit RAW output, S-Log3, S-Cinetone |
| Autofocus | Phase-detect, 759 points, real-time Eye AF (human & animal), subject recognition | Real-time tracking with subject recognition (human, animal) |
| Stabilisation | 5.5-stop IBIS | 5-axis IBIS — 5 stops |
| Burst Rate | 10fps mechanical | 10fps mechanical, 10fps electronic |
| Battery Life | ~600 shots (CIPA) / ~70min continuous 4K recording | ~640 shots (CIPA) |
| Weight | 699g (body, battery, card) | 715g body only (with XLR handle) |
| Dimensions | 128.9 × 96.9 × 80.8mm | 129.7 × 78.0 × 84.5mm |
| Weather Sealed | Yes | Yes |
| Viewfinder | OLED EVF, 9.44M dots, 0.90× magnification — best EVF Sony has made | None — monitor/external EVF use only |
| Screen | 3.0" vari-angle touchscreen, 1.44M dots | 3.0" touchscreen, fully articulating |
| Mount | Sony E-mount | Sony FE mount (full-frame E-mount) |
| Memory Cards | Dual CFexpress Type A / SD UHS-II (both slots) | Dual CFexpress Type A / SD UHS-II slots |
| Connectivity | USB-C (USB 3.2 Gen 2), full-size HDMI, Wi-Fi 6, Bluetooth | USB-C (10Gbps), full-size HDMI, XLR via handle, Bluetooth, Wi-Fi |
Suitability by genre
| Genre | A7S III | FX3 |
|---|---|---|
| Video | — | |
| Wildlife | — | |
| Street | ||
| Portrait | ||
| Travel | ||
| Vlogging & Video | — | |
| Low Light | — | |
| Wedding | — |
More comparisons with A7S III
Camera family history