Ricoh G900 has a
20.0MP (1/2. ) sized BSI-CMOS sensor . On the other hand, Sony RX1 has a
24.0MP Full frame (35.8 x 23.8 mm ) sized CMOS sensor .
Below you can see the G900 and RX1 sensor size comparison.
As seen above, Sony RX1 has a infx Larger sensor area than Ricoh G900. 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.