Sony
A7S III 2020
Best for Professional video & low-light filmmaking
£3389
new today at Clifton Cameras
Decision tools · Compare
A7S III vs FX3
Quick take: The A7S III 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
FX3 2021
Best for Professional video, documentary & cinematic filmmaking
£2999
new today at Wex Photo Video
Price buttons are affiliate links — GearFrame may earn a commission at no extra cost to you. It never affects a score. Learn more
Verdictwhich should you buy?
A7S III — Professional Video & Low-Light Filmmaking: 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.
FX3 — Professional Video, Documentary & Cinematic Filmmaking: 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)
is the right camera for you if…
- 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)
is the right camera for you if…
- 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
Full specificationsthe better value in each row is highlighted
| Specification | A7S IIISony · 2020 | FX3Sony · 2021 |
|---|---|---|
| Price | £3,389 | £2,999Best |
| 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)Best |
| Weight | 699g (with battery and card)Best | 715g (body only) |
| 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 |
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
A7S III
FX3
Portrait
7.5/10
5.7/10
Street
6.2/10
4.3/10
Travel
6.0/10
5.5/10
Wedding & Events
7.5/10
6.0/10
Vlogging & Video
5.9/10
6.1/10
Filmmaking
8.2/10
9.1/10
Documentary
7.7/10
8.0/10
Sports & Action
7.4/10
5.5/10
Landscape
5.5/10
4.7/10
Wildlife
7.5/10
5.8/10
Casual
4.9/10
4.9/10
Food
6.8/10
6.7/10
Macro
5.8/10
5.5/10
Architecture
5.5/10
5.2/10
Astrophotography
7.8/10
6.7/10
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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