Canon EOS R3vs Sigma fpvs A6400
Canon
Canon EOS R3 (2021)
From £5999
Best for Sports & photojournalism professionals
View Canon EOS R3
Sigma
Sigma fp (2019)
From £1499
Best for Creative filmmakers & experimental photographers
View Sigma fp
Which should you buy?
Sports & Photojournalism Professionals — Canon EOS R3 (2021): The pinnacle of Canon's mirrorless lineup for speed — Eye Control AF and 30fps burst in the most rugged body Canon has ever produced.
Creative Filmmakers & Experimental Photographers — Sigma fp (2019): The smallest full-frame camera in the world — Cinema DNG RAW and L-mount flexibility in a pocket-sized body that rewards creative shooters.
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
Canon EOS R3 (2021)
- You shoot sport, motorsport, wildlife, or news at a professional level
- You need Canon's most reliable and fastest autofocus available
- You need extreme weather sealing for demanding shooting conditions
Sigma fp (2019)
- You're a filmmaker building a cinema rig where the smallest full-frame body is essential
- You want L-mount compatibility to pair with Sigma Art or Leica SL lenses
- You prioritise video and cinema colour over stills ergonomics and functionality
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 sigma fp has the highest resolution at 25mp; the a6400 is the most affordable; only the canon eos r3 is weather sealed. Scroll down for the full spec breakdown.
Full specifications
| Specification | Canon EOS R3 (2021) | Sigma fp (2019) | A6400 (2019) |
|---|---|---|---|
| Price | £5,999 | £1,499 | £899 |
| Sensor | 24.1MP full-frame BSI stacked CMOS | 24.6MP full-frame Bayer CMOS | 24.2MP APS-C Exmor CMOS BSI |
| Resolution | 24.1MP | 24.6MP | 24.2MP |
| Video | 6K RAW, 4K/120p, 1080p/180p | 12-bit Cinema DNG RAW, 4K/24p, 1080p/120p | 4K/30p (6K oversampled, no crop), 1080p/120p slow-motion |
| Autofocus | Dual Pixel CMOS AF II with Eye Control AF | Contrast-detect AF with face/eye detection | Phase-detect, 425 points, real-time Eye AF & animal AF |
| Stabilisation | 8-stop IBIS | None (lens-based only) | None (no IBIS) |
| Burst Rate | 30fps electronic / 12fps mechanical | 18fps electronic | 11fps mechanical, 8fps with AF tracking |
| Battery Life | 620 shots (CIPA) | 200 shots (CIPA) | ~410 shots (CIPA) |
| Weight | 1015g body only | 422g body only | 403g (body, battery, card) |
| Dimensions | 150.0 × 142.6 × 87.2mm | 112.6 × 69.9 × 45.3mm | 120.0 × 66.9 × 59.7mm |
| Weather Sealed | Yes | No | No |
| Viewfinder | 0.76" OLED EVF, 5.76M dots, 120fps | None | EVF, 2.36M dots, 0.70× magnification |
| Screen | 3.2" fully articulating touchscreen | 3.15" fixed touchscreen | 3.0" tilting touchscreen, 180° flip for selfie/vlog, 921k dots |
| Mount | Canon RF | Leica L-mount | Sony E-mount |
| Memory Cards | Dual CFexpress Type B | Single SD UHS-II + CFexpress Type B (via adapter) | Single SD UHS-I |
| Connectivity | USB-C 3.2, HDMI full-size, Wi-Fi 6, Bluetooth, LAN | USB-C 3.1, Wi-Fi, Bluetooth | Micro-USB, Wi-Fi, Bluetooth, NFC |
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