BFvs A6400
Sigma
BF (2025)
Starting from £1799 new
Best for Photographers who want to strip back every distraction
View BF
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.
Content Creation & Vlogging — A6400 (2019): The best value APS-C Sony you can buy — especially used. Real-time Eye AF at this price point was transformative when it launched and still makes it one of the most reliable autofocus systems in the lineup.
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
A6400 (2019)
- Vloggers and content creators who need a flip screen and reliable AF
- Photographers upgrading from a compact or smartphone
- Beginners who want room to grow into a full E-mount lens ecosystem
- Anyone prioritising autofocus performance at an accessible price
Quick take: The a6400 has the highest resolution at 24mp; the a6400 is the most affordable; only the bf is weather sealed. Scroll down for the full spec breakdown.
Full specifications
| Specification | BF (2025) | A6400 (2019) |
|---|---|---|
| Price | £1,799 | £899 |
| Sensor | 24MP full-frame BSI CMOS | 24.2MP APS-C Exmor CMOS BSI |
| Resolution | 24.0MP | 24.2MP |
| Video | 4K/30p, 1080p/60p | 4K/30p (6K oversampled, no crop), 1080p/120p slow-motion |
| Autofocus | Phase-detect AF — face and eye detection | Phase-detect, 425 points, real-time Eye AF & animal AF |
| Stabilisation | 5-axis IBIS — 7 stops | None (no IBIS) |
| Burst Rate | 9fps electronic | 11fps mechanical, 8fps with AF tracking |
| Battery Life | ~400 shots (CIPA) | ~410 shots (CIPA) |
| Weight | 427g body only | 403g (body, battery, card) |
| Dimensions | 127.0 × 75.0 × 45.0mm | 120.0 × 66.9 × 59.7mm |
| Weather Sealed | Yes | No |
| Viewfinder | EVF 0.75× 3.68M-dot | EVF, 2.36M dots, 0.70× magnification |
| Screen | 3.15" fully articulating touchscreen — primary interface | 3.0" tilting touchscreen, 180° flip for selfie/vlog, 921k dots |
| Mount | L-mount (Leica/Panasonic/Sigma) | Sony E-mount |
| Memory Cards | Single UHS-II SD slot | Single SD UHS-I |
| Connectivity | USB-C, Wi-Fi, Bluetooth | Micro-USB, Wi-Fi, Bluetooth, NFC |
Suitability by genre
| Genre | BF | A6400 |
|---|---|---|
| Street | ||
| Travel | ||
| Portrait | ||
| Landscape | — | |
| Sports | — | |
| Vlogging & Video | — | |
| Video | — | |
| Wildlife | — |
More comparisons with BF
Camera family history