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, Fujifilm X-Pro3 has a 26.0MP APS-C (23.5 x 15.6 mm ) sized BSI-CMOS sensor and features X-Processor 4 processor.
Another similarity between these two cameras is that both Fujifilm X-Pro3 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 X-Pro3 sensor size comparison.
![Panasonic S5 vs Fujifilm X-Pro3 Sensor Size Comparison]()
Sensor Size and Resolution Comparison image of Panasonic S5 and Fujifilm X-Pro3 Cameras
As seen above, Panasonic S5 has a 2.3x Larger sensor area than Fujifilm X-Pro3. 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.