Canon EOS R3vs Sigma fpvs A7 IV
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.
Portrait & Wedding Photography — A7 IV (2021): The full-frame portrait benchmark — 33MP, AI Eye AF, and exceptional skin-tone rendering in a pro-grade hybrid body.
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
A7 IV (2021)
- You want a high-resolution full-frame all-rounder for portraits, weddings, or travel
- You're stepping up from APS-C or a DSLR and want the best all-round full-frame body under £3,000
- You shoot a mix of stills and video and need a single body that handles both seriously
- You want access to the widest lens ecosystem in the mirrorless market
Quick take: The a7 iv has the highest resolution at 33mp; the sigma fp is the most affordable; only the canon eos r3, a7 iv are weather sealed. Scroll down for the full spec breakdown.
Full specifications
| Specification | Canon EOS R3 (2021) | Sigma fp (2019) | A7 IV (2021) |
|---|---|---|---|
| Price | £5,999 | £1,499 | £2,299 |
| Sensor | 24.1MP full-frame BSI stacked CMOS | 24.6MP full-frame Bayer CMOS | 33MP Full-frame BSI Exmor R CMOS |
| Resolution | 24.1MP | 24.6MP | 33.0MP |
| Video | 6K RAW, 4K/120p, 1080p/180p | 12-bit Cinema DNG RAW, 4K/24p, 1080p/120p | 4K/60p oversampled, 10-bit internal, S-Log3, S-Cinetone |
| Autofocus | Dual Pixel CMOS AF II with Eye Control AF | Contrast-detect AF with face/eye detection | 759-point phase-detect, AI subject recognition |
| Stabilisation | 8-stop IBIS | None (lens-based only) | 5-axis IBIS, 5.5 stops |
| Burst Rate | 30fps electronic / 12fps mechanical | 18fps electronic | 10fps mechanical, 30fps electronic |
| Battery Life | 620 shots (CIPA) | 200 shots (CIPA) | ~580 shots (CIPA) |
| Weight | 1015g body only | 422g body only | 659g body only |
| Dimensions | 150.0 × 142.6 × 87.2mm | 112.6 × 69.9 × 45.3mm | 131.3 × 96.4 × 79.8mm |
| Weather Sealed | Yes | No | Yes |
| Viewfinder | 0.76" OLED EVF, 5.76M dots, 120fps | None | EVF, 3.69M dots, 0.78× magnification |
| Screen | 3.2" fully articulating touchscreen | 3.15" fixed touchscreen | 3.0" vari-angle touchscreen |
| Mount | Canon RF | Leica L-mount | Sony FE (full-frame E-mount) |
| Memory Cards | Dual CFexpress Type B | Single SD UHS-II + CFexpress Type B (via adapter) | Dual slots: CFexpress Type A + SD UHS-II |
| Connectivity | USB-C 3.2, HDMI full-size, Wi-Fi 6, Bluetooth, LAN | USB-C 3.1, Wi-Fi, Bluetooth | USB-C (3.2 Gen 2), Bluetooth, Wi-Fi |
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