BFvs A7S II
Sigma
BF (2025)
Starting from £1799 new
Best for Photographers who want to strip back every distraction
View BF
Sony
A7S II (2015)
Starting from £799 new
Best for Low-light video, documentary & available-light filmmaking
View A7S II
GearScore™ Verdict — Which should you buy?
Photographers Who Want To Strip Back Every Distraction — BF (2025): The most radical camera in years — no dials, no buttons, just a flat aluminium body and total creative minimalism.
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.
Who should buy what
BF (2025)
- Photographers who find camera menus and dials a distraction from the creative process
- L-mount system users who want the lightest, most minimal full-frame body available
- Design enthusiasts who value the object quality and philosophy as much as the output
- Sigma fp/fp L users ready for a more radical step toward minimal photography
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
Quick take: The bf has the highest resolution at 24mp; the a7s ii is the most affordable. Scroll down for the full spec breakdown.
Full specifications
| Specification | BF (2025) | A7S II (2015) |
|---|---|---|
| Price | £1,799 | £799 |
| Sensor | 24MP full-frame BSI CMOS | 12.1MP full-frame BSI Exmor CMOS |
| Resolution | 24.0MP | 12.1MP |
| Video | 4K/30p, 1080p/60p | 4K/30p internal (full sensor readout), 1080p/120p, S-Log2/S-Log3 |
| Autofocus | Phase-detect AF — face and eye detection | 169 phase-detect + 25 contrast AF — limited by modern standards |
| Stabilisation | 5-axis IBIS — 7 stops | 5-axis IBIS — 4.5 stops (first Sony mirrorless with IBIS) |
| Burst Rate | 9fps electronic | 5fps continuous |
| Battery Life | ~400 shots (CIPA) | ~370 shots (CIPA) |
| Weight | 427g body only | 584g body only |
| Dimensions | 127.0 × 75.0 × 45.0mm | 126.9 × 95.7 × 60.3mm |
| Weather Sealed | Yes | Yes |
| Viewfinder | EVF 0.75× 3.68M-dot | EVF, 2.36M dots, 0.71× magnification |
| Screen | 3.15" fully articulating touchscreen — primary interface | 3.0" tilting LCD, 1.23M dots |
| Mount | L-mount (Leica/Panasonic/Sigma) | Sony FE mount (full-frame E-mount) |
| Memory Cards | Single UHS-II SD slot | Dual SD UHS-I slots |
| Connectivity | USB-C, Wi-Fi, Bluetooth | USB Micro-B, Bluetooth (via app), Wi-Fi, 3.5mm mic jack |
Suitability by genre
| Genre | BF | A7S II |
|---|---|---|
| Street | ||
| Travel | — | |
| Portrait | ||
| Landscape | — | |
| Sports | ||
| Vlogging & Video | ||
| Low Light | — | |
| Wedding | — |
GearScore™ suitability scores are based on aggregated purchaser reviews weighted by photography genre. See how scores are calculated →
More comparisons with BF
Camera family history