EOS R100vs A7 IIIvs Sony A9 III
Which should you buy?
First Camera / Beginner Photography — EOS R100 (2023): The R100 does the basics well at the lowest possible price point. Its main value is as a gateway into the Canon RF ecosystem — the lenses you buy now will work on any Canon body you upgrade to later. Modest ambitions, reliably met.
All-Round Photography & Video — A7 III (2018): Still one of the best all-round cameras money can buy — particularly strong used. The A7 III proved that full-frame doesn't have to mean compromises, and nothing at this price point has meaningfully beaten it.
Sports & Action Professionals — Sony A9 III (2023): A paradigm-shifting camera — the global shutter eliminates every rolling shutter limitation that has constrained action photography for years.
Who should buy what
EOS R100 (2023)
- First-time camera buyers stepping up from a smartphone
- Students and hobbyists wanting an affordable starting point
- Anyone who wants to start investing in Canon RF glass on a budget
- Casual photographers who don't need advanced video or speed
A7 III (2018)
- Enthusiast photographers upgrading from APS-C for the first time
- Working photographers who need reliable AF and weather sealing
- Anyone who shoots in low light regularly
- Hybrid shooters needing both stills and video performance
Sony A9 III (2023)
- You shoot professional sport, motorsport, or action and need zero rolling shutter distortion
- You need reliable high-speed flash sync for studio or on-location action work
- You want the absolute pinnacle of Sony's action and sports camera technology
Quick take: The sony a9 iii has the highest resolution at 25mp; the eos r100 is the most affordable; only the a7 iii, sony a9 iii are weather sealed. Scroll down for the full spec breakdown.
Full specifications
| Specification | EOS R100 (2023) | A7 III (2018) | Sony A9 III (2023) |
|---|---|---|---|
| Price | £529 | £1,699 | £5,999 |
| Sensor | 24.1MP APS-C CMOS | 24.2MP Full-Frame Exmor R BSI CMOS | 24.6MP full-frame Exmor RS CMOS (global shutter) |
| Resolution | 24.1MP | 24.2MP | 24.6MP |
| Video | 4K/30p (slight crop), 1080p/60p | 4K/30p (6K oversampled), 1080p/120p slow-motion | 4K/120p, 4K/60p, 1080p/240p |
| Autofocus | Dual Pixel CMOS AF, face detection, subject tracking | Phase-detect, 693 points, real-time Eye AF & animal AF | AI subject recognition AF, 759-point phase-detect |
| Stabilisation | None (no IBIS) | 5-axis IBIS, 5 stops | 8-stop IBIS |
| Burst Rate | 6.5fps mechanical | 10fps with AF/AE tracking | 120fps blackout-free electronic |
| Battery Life | ~270 shots (CIPA) | ~710 shots (CIPA) | 530 shots (CIPA) |
| Weight | 356g (body, battery, card) | 565g (body, battery, card) | 703g body only |
| Dimensions | 116.3 × 85.5 × 68.8mm | 126.9 × 95.6 × 73.7mm | 136.1 × 96.9 × 82.9mm |
| Weather Sealed | No | Yes | Yes |
| Viewfinder | EVF, 2.36M dots, 0.59× magnification | EVF, 2.36M dots, 0.78× magnification | 0.64" Quad-XGA OLED EVF, 9.44M dots |
| Screen | 3.0" fixed touchscreen, 1.04M dots | 3.0" tilting touchscreen, 921k dots | 3.2" fully articulating touchscreen |
| Mount | Canon RF-mount | Sony E-mount | Sony FE (E-mount) |
| Memory Cards | Single SD UHS-II | Dual SD (UHS-II slot 1, UHS-I slot 2) | Dual CFexpress Type A / SD UHS-II |
| Connectivity | USB-C, Wi-Fi, Bluetooth | USB-C (USB 3.2), Wi-Fi, Bluetooth, NFC | USB-C 3.2, HDMI A, Wi-Fi 6, Bluetooth 5.3 |
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