Both Olympus XZ-2 iHS and Nikon D90 have 12.0 MP resolution sensors but Olympus XZ-2 iHS's sensor is 1/1.7-inch (7.44 x 5.58 mm ) and Nikon D90's sensor is APS-C (23.6 x 15.8 mm ).
Since Nikon D90's has a larger sensor area with the same resolution, this means that it also has a larger pixel area hence better light collecting capacity for a given aperture compared to Olympus XZ-2 iHS.
Below you can see the XZ-2 iHS and D90 sensor size comparison.
As seen above, Nikon D90 has a 9.0x Larger sensor area than Olympus XZ-2 iHS. Larger sensors give photographer more control on the depth of field and blurry background compared to smaller sensor when shot in same focal length and aperture.
DxOMark Sensor Scores
DxOMark is a benchmark that scientifically assesses image quality of camera sensors. It scores camera sensors for color depth (DXO Portrait), dynamic range (DXO Landscape) and low-light sensitivity (DXO Sports), and also gives them an overall score. Olympus XZ-2 iHS and Nikon D90 sensors have been tested by DxO and the results show that D90 has a better overall score of 73, 24 points higher compared to XZ-2 iHS's score of 49.
Model |
Overall |
Color Depth |
Dynamic Range |
Low-light ISO |
Olympus XZ-2 iHS |
49 |
20.4 bits |
11.3 Evs |
216 ISO |
Nikon D90 |
73 |
22.7 bits |
12.5 Evs |
977 ISO |