Sony A230 has a
10.0MP APS-C (23.5 x 15.7 mm ) sized CCD sensor and features Bionz processor. On the other hand, Pentax K-7 has a
15.0MP APS-C (23.4 x 15.6 mm ) sized CMOS sensor and features Prime II processor.
Pentax K-7's sensor provides 5MP more than Sony A230'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 A230 and K-7 sensor size comparison.
Sensor Size and Resolution Comparison image of Sony A230 and Pentax K-7 Cameras
Sony A230 and Pentax K-7 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
Both Sony A230 and Pentax K-7 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, A230 has scored 63, 2 points higher than K-7.
Model
Overall
Color Depth
Dynamic Range
Low-light ISO
Sony A230
63
22.3 bits
11.4 Evs
531 ISO
Pentax K-7
61
22.6 bits
10.6 Evs
536 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 A230
or the
Pentax K-7 ,
including hyperfocal distance.
