FujiFilm S2800HD has a
14.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CCD sensor . On the other hand, Ricoh GR II has a
16.0MP APS-C (23.7 x 15.7 mm ) sized CMOS sensor and features GR Engine V processor.
Below you can see the S2800HD and GR II sensor size comparison.
As seen above, Ricoh GR II has a 13.3x Larger sensor area than FujiFilm S2800HD. 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.