Ricoh GXR A16 24-85mm has a
16.0MP APS-C (23.6 x 15.7 mm ) sized CMOS sensor and features Smooth Imaging Engine IV processor. On the other hand, Canon G15 has a
12.0MP 1/1.7-inch (7.44 x 5.58 mm ) sized CMOS sensor and features Digic 5 processor.
Below you can see the GXR A16 24-85mm F3.5-5.5 and G15 sensor size comparison.
As seen above, Ricoh GXR A16 24-85mm has a 8.9x Larger sensor area than Canon G15. 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.