EOS R100vs OM System TG-7vs A7 III
OM System
OM System TG-7 (2023)
From £449
Best for Adventure, underwater & outdoor use
View OM System TG-7
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.
Adventure, Underwater & Outdoor Use — OM System TG-7 (2023): Waterproof to 15m, freezeproof and shockproof — the TG-7 is the most capable rugged compact for adventure and outdoor use.
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.
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
OM System TG-7 (2023)
- You dive, surf, kayak, ski, or hike and need a camera that genuinely survives anything
- You want a waterproof backup or travel camera that doesn't require a separate housing
- You need a rugged compact for adventure, outdoor, and underwater activities
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
Quick take: The a7 iii has the highest resolution at 24mp; the om system tg-7 is the most affordable; only the om system tg-7, a7 iii are weather sealed. Scroll down for the full spec breakdown.
Full specifications
| Specification | EOS R100 (2023) | OM System TG-7 (2023) | A7 III (2018) |
|---|---|---|---|
| Price | £529 | £449 | £1,699 |
| Sensor | 24.1MP APS-C CMOS | 12MP BSI CMOS | 24.2MP Full-Frame Exmor R BSI CMOS |
| Resolution | 24.1MP | 12.0MP | 24.2MP |
| Video | 4K/30p (slight crop), 1080p/60p | 4K/30p, 1080p/120p | 4K/30p (6K oversampled), 1080p/120p slow-motion |
| Autofocus | Dual Pixel CMOS AF, face detection, subject tracking | Hybrid phase/contrast AF | Phase-detect, 693 points, real-time Eye AF & animal AF |
| Stabilisation | None (no IBIS) | Digital IS | 5-axis IBIS, 5 stops |
| Burst Rate | 6.5fps mechanical | 20fps | 10fps with AF/AE tracking |
| Battery Life | ~270 shots (CIPA) | 340 shots (CIPA) | ~710 shots (CIPA) |
| Weight | 356g (body, battery, card) | 253g | 565g (body, battery, card) |
| Dimensions | 116.3 × 85.5 × 68.8mm | 113.0 × 66.5 × 32.7mm | 126.9 × 95.6 × 73.7mm |
| Weather Sealed | No | Yes | Yes |
| Viewfinder | EVF, 2.36M dots, 0.59× magnification | None | EVF, 2.36M dots, 0.78× magnification |
| Screen | 3.0" fixed touchscreen, 1.04M dots | 3.0" fixed TFT LCD | 3.0" tilting touchscreen, 921k dots |
| Mount | Canon RF-mount | Fixed 25mm-equiv f/2.0 lens (4× optical zoom) | Sony E-mount |
| Memory Cards | Single SD UHS-II | Single SD UHS-I | Dual SD (UHS-II slot 1, UHS-I slot 2) |
| Connectivity | USB-C, Wi-Fi, Bluetooth | USB-C, Wi-Fi, Bluetooth | USB-C (USB 3.2), Wi-Fi, Bluetooth, NFC |
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