The Olympus PEN E-P3 is 7.5 mm narrower, 27.4 mm shorter, 39.4 mm thinner and 389 g lighter than the Pentax K-7.
| Pentax K-7 | Olympus PEN E-P3 | |
|---|---|---|
| Size (W × H × D) | 129.5 × 96.5 × 73.7 mm | 122 × 69.1 × 34.3 mm |
| Weight | 758 g | 369 g |
| Lens | Pentax K | Micro Four Thirds |
| Sensor | — | Four Thirds |
| Announced | 2009 | 2011 |