Olympus E-M1 II has a
20.0MP Four Thirds (17.4 x 13 mm ) sized CMOS sensor and features TruePic VIII processor. On the other hand, Nikon D800 has a
36.0MP Full frame (35.9 x 24 mm ) sized CMOS sensor and features Expeed 3 processor.
Nikon D800's sensor provides 16MP more than Olympus E-M1 II's sensor, which gives a significant advantage in real life. You can print your images larger or crop more freely.
On the other hand, please keep in mind that Max sensor resolution is not the only determinant of resolving power. Factors such as the optical elements, low pass filter, pixel size and sensor technology also affects the final resolution of the captured image.
Another difference between these two cameras is that Olympus E-M1 II's sensor lacks anti-alias (Low-Pass) filter. Removing anti-alias filter increases the sharpness and level of detail but at the same time, it increases the chance of moiré occurring in certain scenes.
Below you can see the E-M1 II and D800 sensor size comparison.
As seen above, Nikon D800 has a 3.8x Larger sensor area than Olympus E-M1 II. 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 E-M1 II and Nikon D800 sensors have been tested by DxO and the results show that D800 has a better overall score of 95, 15 points higher compared to E-M1 II's score of 80.
Model |
Overall |
Color Depth |
Dynamic Range |
Low-light ISO |
Olympus E-M1 II |
80 |
23.7 bits |
12.8 Evs |
1312 ISO |
Nikon D800 |
95 |
25.3 bits |
14.4 Evs |
2853 ISO |