Sony A330 has a
10.0MP APS-C (23.5 x 15.7 mm ) sized CCD sensor and features Bionz processor. On the other hand, Nikon D3300 has a
24.0MP APS-C (23.5 x 15.6 mm ) sized CMOS sensor and features Expeed 4 processor.
Nikon D3300's sensor provides 14MP more than Sony A330'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.
One other difference between these two cameras that is worth mentioning is that Nikon D3300's sensor doesn't have an 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 A330 and D3300 sensor size comparison.
Sensor Size and Resolution Comparison image of Sony A330 and Nikon D3300 Cameras
Sony A330 and Nikon D3300 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. Sony A330 and Nikon D3300 sensors have been tested by DxO and the results show that D3300 has a better overall score of 82, 18 points higher compared to A330's score of 64.
Model
Overall
Color Depth
Dynamic Range
Low-light ISO
Sony A330
64
22.4 bits
11.5 Evs
535 ISO
Nikon D3300
82
24.3 bits
12.8 Evs
1385 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 A330
or the
Nikon D3300 ,
including hyperfocal distance.
