Nikon D3500 has a
24.0MP APS-C (23.5 x 15.6 mm ) sized CMOS sensor and features Expeed 4 processor. On the other hand, Pentax K-S2 has a
20.0MP APS-C (23.5 x 15.6 mm ) sized CMOS sensor and features PRIME MII processor.
Another similarity between these two cameras is that both Pentax K-S2 and Nikon D3500 sensors lack anti-alias (Low-Pass) filters. 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 D3500 and K-S2 sensor size comparison.
Sensor Size and Resolution Comparison image of Nikon D3500 and Pentax K-S2 Cameras
Nikon D3500 and Pentax K-S2 have the same sensor sizes so they will provide same level of control over the depth of field when used with same focal length and aperture. On the other hand, since Pentax K-S2 has 20% larger pixel area (18.37µm 2 vs 15.28µm 2 ) compared to Nikon D3500, it has larger pixel area to collect light hence potential to have less noise in low light / High ISO images.
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 D3500
or the
Pentax K-S2 ,
including hyperfocal distance.
