Pentax K-S1 has a
20.0MP APS-C (23.5 x 15.6 mm ) sized CMOS sensor and features Prime MII processor. On the other hand, Canon SL2 has a
24.0MP APS-C (22.3 x 14.9 mm ) sized CMOS sensor and features DIGIC 7 processor.
Another difference between these two cameras is that Pentax K-S1's sensor lacks 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-S1 and SL2 sensor size comparison.
Sensor Size and Resolution Comparison image of Pentax K-S1 and Canon SL2 Cameras
As seen above, Pentax K-S1 has a 1.1x Larger sensor area than Canon SL2. Larger sensors give photographer more control on the depth of field and blurry background compared to smaller sensor when shot in 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. Pentax K-S1 and Canon SL2 sensors have been tested by DxO and the results show that SL2 has a better overall score of 79, 1 points higher compared to K-S1's score of 78.
Model
Overall
Color Depth
Dynamic Range
Low-light ISO
Pentax K-S1
78
23.5 bits
13.0 Evs
1061 ISO
Canon SL2
79
23.6 bits
13.4 Evs
1041 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-S1
or the
Canon SL2 ,
including hyperfocal distance.