Pentax ist DL2 has a
6.0MP APS-C (23.5 x 15.7 mm ) sized CCD sensor . 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 18MP more than Pentax ist DL2'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 ist DL2 and A77 sensor size comparison.
Sensor Size and Resolution Comparison image of Pentax ist DL2 and Sony A77 Cameras
Pentax ist DL2 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
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. Pentax ist DL2 and Sony A77 sensors have been tested by DxO and the results show that A77 has a better overall score of 78, 13 points higher compared to ist DL2's score of 65.
Model
Overall
Color Depth
Dynamic Range
Low-light ISO
Pentax ist DL2
65
22.9 bits
11.1 Evs
639 ISO
Sony A77
78
24.0 bits
13.2 Evs
801 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
Pentax ist DL2
or the
Sony A77 ,
including hyperfocal distance.
