Sony A68 has a
24.0MP APS-C (23.5 x 15.6 mm ) sized CMOS sensor and features Bionz X processor. On the other hand, Pentax K-5 has a
16.0MP APS-C (23.7 x 15.7 mm ) sized CMOS sensor and features Prime II processor.
Sony A68's sensor provides 8MP more than Pentax K-5'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 A68 and K-5 sensor size comparison.
Sensor Size and Resolution Comparison image of Sony A68 and Pentax K-5 Cameras
Sony A68 and Pentax K-5 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 A68 and Pentax K-5 sensors have been tested by DxO and the results show that K-5 has a better overall score of 82, 3 points higher compared to A68's score of 79.
Model
Overall
Color Depth
Dynamic Range
Low-light ISO
Sony A68
79
24.1 bits
13.5 Evs
701 ISO
Pentax K-5
82
23.7 bits
14.1 Evs
1162 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 A68
or the
Pentax K-5 ,
including hyperfocal distance.
