Pentax K-70 has a
24.0MP APS-C (23.5 x 15.6 mm ) sized CMOS sensor and features PRIME MII 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.
Another similarity between these two cameras is that both Pentax K-S1 and Pentax K-70 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 K-70 and K-S1 sensor size comparison.
Sensor Size and Resolution Comparison image of Pentax K-70 and Pentax K-S1 Cameras
Pentax K-70 and Pentax K-S1 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-S1 has 20% larger pixel area (18.37µm 2 vs 15.28µm 2 ) compared to Pentax K-70, 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
Pentax K-70
or the
Pentax K-S1 ,
including hyperfocal distance.
