Panasonic S5 has a 24.0MP Full frame (35.6 x 23.8 mm ) sized CMOS sensor and features Venus Engine 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 Panasonic S5 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 moire occurring in certain scenes.
Below you can see the S5 and K-S1 sensor size comparison.
![Panasonic S5 vs Pentax K-S1 Sensor Size Comparison]()
Sensor Size and Resolution Comparison image of Panasonic S5 and Pentax K-S1 Cameras
As seen above, Panasonic S5 has a 2.3x Larger sensor area than Pentax K-S1. 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.