Nikon D50 has a
6.0MP APS-C (23.7 x 15.5 mm ) sized CCD sensor . On the other hand, Pentax K-3 II has a
24.0MP APS-C (23.5 x 15.6 mm ) sized CMOS sensor and features Prime III processor.
Pentax K-3 II's sensor provides 18MP more than Nikon D50'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.
One other difference between these two cameras that is worth mentioning is that Pentax K-3 II's sensor doesn't have an anti-alias (Low-Pass) filter. Removing anti-alias filter increases the sharpness and level of detail but at the same time, it increases the chance of moiré occurring in certain scenes.
Below you can see the D50 and K-3 II sensor size comparison.
Sensor Size and Resolution Comparison image of Nikon D50 and Pentax K-3 II Cameras
Nikon D50 and Pentax K-3 II 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 D50 and Pentax K-3 II sensors have been tested by DxO and the results show that K-3 II has a better overall score of 80, 25 points higher compared to D50's score of 55.
Model
Overall
Color Depth
Dynamic Range
Low-light ISO
Nikon D50
55
20.9 bits
10.8 Evs
560 ISO
Pentax K-3 II
80
23.6 bits
13.6 Evs
1106 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 D50
or the
Pentax K-3 II ,
including hyperfocal distance.
