Pentax K20D has a
15.0MP APS-C (23.4 x 15.6 mm ) sized CMOS sensor . On the other hand, Pentax K-30 has a
16.0MP APS-C (23.7 x 15.7 mm ) sized CMOS sensor and features Prime M processor.
Below you can see the K20D and K-30 sensor size comparison.
Sensor Size and Resolution Comparison image of Pentax K20D and Pentax K-30 Cameras
Pentax K20D and Pentax K-30 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 K20D and Pentax K-30 sensors have been tested by DxO and the results show that K-30 has a better overall score of 79, 14 points higher compared to K20D's score of 65.
Model
Overall
Color Depth
Dynamic Range
Low-light ISO
Pentax K20D
65
22.9 bits
11.1 Evs
639 ISO
Pentax K-30
79
23.7 bits
13.0 Evs
1129 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 K20D
or the
Pentax K-30 ,
including hyperfocal distance.
