Canon 100D has a 18.0MP APS-C (22.3 x 14.9 mm ) sized CMOS sensor and features Digic 5 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 100D and K-S1 sensor size comparison.
Sensor Size and Resolution Comparison image of Canon 100D and Pentax K-S1 Cameras
As seen above, Pentax K-S1 has a 1.1x Larger sensor area than Canon 100D. 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. Canon 100D and Pentax K-S1 sensors have been tested by DxO and the results show that K-S1 has a better overall score of 78, 15 points higher compared to 100D's score of 63.
| Model |
Overall |
Color Depth |
Dynamic Range |
Low-light ISO |
|
Canon 100D |
63 |
21.8 bits |
11.3 Evs |
843 ISO |
|
Pentax K-S1 |
78 |
23.5 bits |
13.0 Evs |
1061 ISO |