Nikon D40 has a
6.0MP APS-C (23.7 x 15.5 mm ) sized CCD sensor . On the other hand, Pentax K200D has a
10.0MP APS-C (23.5 x 15.7 mm ) sized CCD sensor .
Below you can see the D40 and K200D sensor size comparison.
Sensor Size and Resolution Comparison image of Nikon D40 and Pentax K200D Cameras
Nikon D40 and Pentax K200D 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 D40 and Pentax K200D sensors have been tested by DxO and the results show that K200D has a better overall score of 64, 8 points higher compared to D40's score of 56.
Model
Overall
Color Depth
Dynamic Range
Low-light ISO
Nikon D40
56
21.0 bits
11.0 Evs
561 ISO
Pentax K200D
64
22.4 bits
11.4 Evs
561 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 D40
or the
Pentax K200D ,
including hyperfocal distance.
