Sony A77 II has a
24.0MP APS-C (23.5 x 15.6 mm ) sized CMOS sensor and features Bionz X processor. On the other hand, Nikon D3 has a
12.0MP Full frame (36 x 23.9 mm ) sized CMOS sensor and features Expeed processor.
Sony A77 II's sensor provides 12MP more than Nikon D3'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.
Below you can see the A77 II and D3 sensor size comparison.
Sensor Size and Resolution Comparison image of Sony A77 II and Nikon D3 Cameras
As seen above, Nikon D3 has a 2.3x Larger sensor area than Sony A77 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
Both Sony A77 II and Nikon D3 sensors have been tested by DxoMark. DxoMark 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. Of the two cameras that we are comparing, A77 II has scored 82, 1 points higher than D3.
Model
Overall
Color Depth
Dynamic Range
Low-light ISO
Sony A77 II
82
24.4 bits
13.4 Evs
1013 ISO
Nikon D3
81
23.5 bits
12.2 Evs
2290 ISO
Sensor size sets the circle of confusion, so it drives how much depth of field each
of these bodies gives you at a given aperture. You can calculate it exactly for the
Sony A77 II
or the
Nikon D3 ,
including hyperfocal distance.
One thing to watch when comparing these two: they have different sensor sizes
(APS-C versus Full frame),
so compare them at the same framing rather than the same focal length.
Put the same focal length on the smaller sensor and it will show less depth of
field, not more, because it also crops tighter. The calculator shows the
full frame equivalent focal length for each body so you can match the framing.
