Pentax K10D has a
10.0MP APS-C (23.5 x 15.7 mm ) sized CCD sensor . On the other hand, Pentax K-r has a
12.0MP APS-C (23.6 x 15.8 mm ) sized CMOS sensor and features Prime II processor.
Below you can see the K10D and K-r sensor size comparison.
Sensor Size and Resolution Comparison image of Pentax K10D and Pentax K-r Cameras
Pentax K10D and Pentax K-r 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 K10D and Pentax K-r sensors have been tested by DxO and the results show that K-r has a better overall score of 72, 6 points higher compared to K10D's score of 66.
Model
Overall
Color Depth
Dynamic Range
Low-light ISO
Pentax K10D
66
22.7 bits
11.6 Evs
522 ISO
Pentax K-r
72
22.9 bits
12.4 Evs
755 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 K10D
or the
Pentax K-r ,
including hyperfocal distance.