The OM System OM-3 is 4.8 mm wider, 14.6 mm shorter, 27.7 mm thinner and 324 g lighter than the Pentax K-3 III.
| Pentax K-3 III | OM System OM-3 | |
|---|---|---|
| Size (W × H × D) | 134.5 × 103.5 × 73.5 mm | 139.3 × 88.9 × 45.8 mm |
| Weight | 820 g | 496 g |
| Lens | Pentax K | Micro Four Thirds |
| Sensor | — | Four Thirds |
| Announced | 2021 | 2025 |