Nikon D200 has a
10.0MP APS-C (23.6 x 15.8 mm ) sized CCD sensor . On the other hand, Pentax K20D has a
15.0MP APS-C (23.4 x 15.6 mm ) sized CMOS sensor .
Pentax K20D's sensor provides 5MP more than Nikon D200'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 D200 and K20D sensor size comparison.
Sensor Size and Resolution Comparison image of Nikon D200 and Pentax K20D Cameras
Nikon D200 and Pentax K20D 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. Nikon D200 and Pentax K20D sensors have been tested by DxO and the results show that K20D has a better overall score of 65, 1 points higher compared to D200's score of 64.
Model
Overall
Color Depth
Dynamic Range
Low-light ISO
Nikon D200
64
22.3 bits
11.5 Evs
583 ISO
Pentax K20D
65
22.9 bits
11.1 Evs
639 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
Nikon D200
or the
Pentax K20D ,
including hyperfocal distance.
