Pentax K-500 has a
16.0MP APS-C (23.7 x 15.7 mm ) sized CMOS sensor and features PRIME M processor. On the other hand, Pentax K-S1 has a
20.0MP APS-C (23.5 x 15.6 mm ) sized CMOS sensor and features Prime MII processor.
One other difference between these two cameras that is worth mentioning is that Pentax K-S1'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 K-500 and K-S1 sensor size comparison.
Sensor Size and Resolution Comparison image of Pentax K-500 and Pentax K-S1 Cameras
Pentax K-500 and Pentax K-S1 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
Both Pentax K-500 and Pentax K-S1 sensors have been tested by DxoMark. DxoMark 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. Of the two cameras that we are comparing, K-500 has scored 79, 1 points higher than K-S1.
Model
Overall
Color Depth
Dynamic Range
Low-light ISO
Pentax K-500
79
23.7 bits
13.1 Evs
1087 ISO
Pentax K-S1
78
23.5 bits
13.0 Evs
1061 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 K-500
or the
Pentax K-S1 ,
including hyperfocal distance.
