Where they actually differ
The most decisive specs, ranked by how much they matter — before the full spec table.
| Spec | Canon - EOS R1 | Sony - α9 III |
|---|---|---|
| Weight | 1115 g | 703 g |
| AF points | 1053 | 759 |
| Max video | 6K | 4K120 |
Between the EOS R1 and α9 III, the EOS R1 comes out ahead in af points / max video, while the α9 III wins on weight. Overall, the EOS R1 scores 73.5 and the α9 III scores 71.7 on our Mars Score.
Which should you buy?
These two are nearly even on the Mars Score (73.5 vs 71.7). The decision is not about overall quality — both clear the bar — it is about which specific trade-offs fit your use.
Pick the EOS R1 if you care most about af points / max video. The biggest gaps in its favor are af points, max video. The single most decisive one: AF points — 38.74% more. 1053 vs 759.
Pick the α9 III if you carry the device everywhere and weight or thickness has been the deciding factor before. Its strongest claims are weight. The single most decisive one: Weight — 412.00 g less. 703 vs 1115.
Both ship with comparable sensor size, megapixels, in-body stabilization, so those specs do not separate the two — focus on the differences below.
Bottom line: there is no wrong answer here — match the spec advantages to how you actually use the product. The Mars Score parity says both are well-rounded; the differences are about trade-offs, not quality.
Which should you buy: Canon - EOS R1 or Sony - α9 III?
Canon - EOS R1 leads the current Mars Score by 1.8 points.The more useful decision is the trade-off behind that result: compare max video, weight against the way you will actually use the product.
Choose Canon - EOS R1 if…
Canon - EOS R1 has the measurable edge on af points, max video.
Choose Sony - α9 III if…
Sony - α9 III has the measurable edge on weight g.
This is a structured comparison of the published catalog values. It is not a claim of identical real-world performance across every workload; use the linked spec drill-downs and methodology page to inspect the inputs.
Why Canon - EOS R1 wins
- ▲AF points — 38.74% more. 1053 vs 759.
- ▲Max video: 6K (vs 4K120).
Why Sony - α9 III wins
- ▲Weight — 412.00 g less. 703 vs 1115.
Spec comparison
Sensor
| Spec | Canon - EOS R1 | Sony - α9 III |
|---|---|---|
| Sensor sizeⓘ | Full Frame | Full Frame |
| Megapixels | 24 MP | 24 MP |
| Max ISO | 204800lead | 51200 |
Video
| Spec | Canon - EOS R1 | Sony - α9 III |
|---|---|---|
| Max video | 6Klead | 4K120 |
| RAW video | true | true |
| Log profileⓘ | true | true |
Autofocus
| Spec | Canon - EOS R1 | Sony - α9 III |
|---|---|---|
| AF pointsⓘ | 1053lead | 759 |
| Eye AFⓘ | true | true |
| In-body stabilizationⓘ | true | true |
Body & Controls
| Spec | Canon - EOS R1 | Sony - α9 III |
|---|---|---|
| Weight | 1115 g | 703 glead |
| Weather sealedⓘ | true | true |
| Dual card slotsⓘ | true | true |