Both Fujifilm S1 and Panasonic G7 have 16.0 MP resolution sensors but Fujifilm S1's sensor is 1/2.3" (6.17 x 4.55 mm ) and Panasonic G7's sensor is Four Thirds (17.3 x 13 mm ).
Since Panasonic G7's has a larger sensor area with the same resolution, this means that it also has a larger pixel area hence better light collecting capacity for a given aperture compared to Fujifilm S1.
Below you can see the S1 and G7 sensor size comparison.
As seen above, Panasonic G7 has a 8.0x Larger sensor area than Fujifilm 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.