Nikon D3S has a
12.0MP Full frame (36 x 23.9 mm ) sized CMOS sensor and features Expeed processor. On the other hand, Sony A99 has a
24.0MP Full frame (35.8 x 23.8 mm ) sized CMOS sensor and features Bionz processor.
Sony A99's sensor provides 12MP more than Nikon D3S'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 D3S and A99 sensor size comparison.
Sensor Size and Resolution Comparison image of Nikon D3S and Sony A99 Cameras
Nikon D3S and Sony A99 have almost the same sensor size, so neither of them has any significant advantage over the other in terms of providing control over depth of field when used with the 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. Nikon D3S and Sony A99 sensors have been tested by DxO and the results show that A99 has a better overall score of 89, 7 points higher compared to D3S's score of 82.
Model
Overall
Color Depth
Dynamic Range
Low-light ISO
Nikon D3S
82
23.5 bits
12.0 Evs
3253 ISO
Sony A99
89
25.0 bits
14.0 Evs
1555 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
Nikon D3S
or the
Sony A99 ,
including hyperfocal distance.
