A7S IIvs FX3
Sony
A7S II (2015)
Starting from £799 new
Best for Low-light video, documentary & available-light filmmaking
View A7S II
VS
Sony
FX3 (2021)
Starting from £3799 new
Best for Professional video, documentary & cinematic filmmaking
View FX3
GearScore™ Verdict — Which should you buy?
Low-Light Video, Documentary & Available-Light Filmmaking — A7S II (2015): 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.
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 II (2015)
- 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
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 ii is the most affordable. Scroll down for the full spec breakdown.
Full specifications
| Specification | A7S II (2015) | FX3 (2021) |
|---|---|---|
| Price | £799 | £3,799 |
| Sensor | 12.1MP full-frame BSI Exmor CMOS | 12.1MP full-frame BSI Exmor R CMOS (same as A7S III) |
| Resolution | 12.1MP | 12.1MP |
| Video | 4K/30p internal (full sensor readout), 1080p/120p, S-Log2/S-Log3 | 4K/120p, 4K/60p 10-bit, 12-bit RAW output, S-Log3, S-Cinetone |
| Autofocus | 169 phase-detect + 25 contrast AF — limited by modern standards | Real-time tracking with subject recognition (human, animal) |
| Stabilisation | 5-axis IBIS — 4.5 stops (first Sony mirrorless with IBIS) | 5-axis IBIS — 5 stops |
| Burst Rate | 5fps continuous | 10fps mechanical, 10fps electronic |
| Battery Life | ~370 shots (CIPA) | ~640 shots (CIPA) |
| Weight | 584g body only | 715g body only (with XLR handle) |
| Dimensions | 126.9 × 95.7 × 60.3mm | 129.7 × 78.0 × 84.5mm |
| Weather Sealed | Yes | Yes |
| Viewfinder | EVF, 2.36M dots, 0.71× magnification | None — monitor/external EVF use only |
| Screen | 3.0" tilting LCD, 1.23M dots | 3.0" touchscreen, fully articulating |
| Mount | Sony FE mount (full-frame E-mount) | Sony FE mount (full-frame E-mount) |
| Memory Cards | Dual SD UHS-I slots | Dual CFexpress Type A / SD UHS-II slots |
| Connectivity | USB Micro-B, Bluetooth (via app), Wi-Fi, 3.5mm mic jack | USB-C (10Gbps), full-size HDMI, XLR via handle, Bluetooth, Wi-Fi |
Suitability by genre
| Genre | A7S II | FX3 |
|---|---|---|
| Vlogging & Video | ||
| Low Light | ||
| Wedding | ||
| Portrait | ||
| Street | ||
| Sports | — | |
| Travel | — |
More comparisons with A7S II
Camera family history