Both Ricoh WG-5 GPS and Nikon W300 have 16.0 MP resolution sensors but Ricoh WG-5 GPS's sensor is (1/2. ) and Nikon W300's sensor is 1/2.3 (6.17 x 4.55 mm ).
Since Nikon W300'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 Ricoh WG-5 GPS.
Below you can see the WG-5 GPS and W300 sensor size comparison.
As seen above, Nikon W300 has a infx Larger sensor area than Ricoh WG-5 GPS. 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.