The Olympus OM-D E-M5 is 6 mm narrower, 6.9 mm shorter, 36.8 mm thinner and 160 g lighter than the Nikon D5100.
| Nikon D5100 | Olympus OM-D E-M5 | |
|---|---|---|
| Size (W × H × D) | 127 × 96.5 × 78.7 mm | 121 × 89.6 × 41.9 mm |
| Weight | 560 g | 400 g |
| Lens | Nikon F | Micro Four Thirds |
| Sensor | — | Four Thirds |
| Announced | 2011 | 2012 |