EOS R8vs Sigma fpvs A7S III
Sigma
Sigma fp (2019)
From £1499
Best for Creative filmmakers & experimental photographers
View Sigma fp
Which should you buy?
Full-Frame Entry — EOS R8 (2023): Canon's most affordable full-frame mirrorless — 4K/60p 10-bit and class-leading Dual Pixel AF at an accessible entry price.
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.
Professional Video & Low-Light Filmmaking — A7S III (2020): If video is your primary discipline, the A7S III is the camera. 4K/120p at 10-bit in a weather-sealed body with a 9.44M dot EVF is an extraordinary package. The 12MP sensor isn't limiting for video — and it's usable at ISO 409,600 in a pinch.
Who should buy what
EOS R8 (2023)
- You want full-frame image quality on a tight budget
- You shoot mainly in good light and can live without built-in stabilisation
- You primarily shoot stills with occasional video
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
A7S III (2020)
- Filmmakers and videographers who need 4K/120p at 10-bit
- Event videographers who shoot in dark venues regularly
- Documentary filmmakers who need reliable AF and weather sealing
- Hybrid shooters where video is primary and stills are secondary
Quick take: The sigma fp has the highest resolution at 25mp; the eos r8 is the most affordable; only the a7s iii is weather sealed. Scroll down for the full spec breakdown.
Full specifications
| Specification | EOS R8 (2023) | Sigma fp (2019) | A7S III (2020) |
|---|---|---|---|
| Price | £1,099 | £1,499 | £2,999 |
| Sensor | 24.2MP Full-frame BSI CMOS | 24.6MP full-frame Bayer CMOS | 12.1MP Full-Frame BSI CMOS (12-bit, back-illuminated) |
| Resolution | 24.2MP | 24.6MP | 12.1MP |
| Video | 4K/60p oversampled 10-bit, FHD/180p | 12-bit Cinema DNG RAW, 4K/24p, 1080p/120p | 4K/120p 10-bit, 4K/60p 10-bit S-Cinetone/S-Log3, 1080p/240p |
| Autofocus | Dual Pixel CMOS AF II, 1053 zones, eye/face/subject tracking | Contrast-detect AF with face/eye detection | Phase-detect, 759 points, real-time Eye AF (human & animal), subject recognition |
| Stabilisation | None (no IBIS) | None (lens-based only) | 5.5-stop IBIS |
| Burst Rate | 6fps mechanical, 40fps electronic | 18fps electronic | 10fps mechanical |
| Battery Life | ~220 shots (CIPA) | 200 shots (CIPA) | ~600 shots (CIPA) / ~70min continuous 4K recording |
| Weight | 461g body only | 422g body only | 699g (body, battery, card) |
| Dimensions | 132.5 × 86.1 × 70.0mm | 112.6 × 69.9 × 45.3mm | 128.9 × 96.9 × 80.8mm |
| Weather Sealed | No | No | Yes |
| Viewfinder | EVF, 2.36M dots, 0.59× | None | OLED EVF, 9.44M dots, 0.90× magnification — best EVF Sony has made |
| Screen | 3.0" fully articulating touchscreen | 3.15" fixed touchscreen | 3.0" vari-angle touchscreen, 1.44M dots |
| Mount | Canon RF mount (full-frame) | Leica L-mount | Sony E-mount |
| Memory Cards | Single SD UHS-II slot | Single SD UHS-II + CFexpress Type B (via adapter) | Dual CFexpress Type A / SD UHS-II (both slots) |
| Connectivity | USB-C, Bluetooth, Wi-Fi | USB-C 3.1, Wi-Fi, Bluetooth | USB-C (USB 3.2 Gen 2), full-size HDMI, Wi-Fi 6, Bluetooth |
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