Pentax K-500 has a
16.0MP APS-C (23.7 x 15.7 mm ) sized CMOS sensor and features PRIME M processor. On the other hand, Sony A77 has a
24.0MP APS-C (23.5 x 15.6 mm ) sized CMOS sensor and features Bionz processor.
Sony A77's sensor provides 8MP more than Pentax K-500'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 K-500 and A77 sensor size comparison.
Pentax K-500 and Sony A77 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 Pentax K-500 and Sony A77 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, K-500 has scored 79, 1 points higher than A77.
Model |
Overall |
Color Depth |
Dynamic Range |
Low-light ISO |
Pentax K-500 |
79 |
23.7 bits |
13.1 Evs |
1087 ISO |
Sony A77 |
78 |
24.0 bits |
13.2 Evs |
801 ISO |