Ricoh CX5 has a
10.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CMOS sensor and features Smooth Imaging Engine IV processor. On the other hand, Ricoh CX1 has a
9.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CMOS sensor and features Smooth Imaging Engine IV processor.
Below you can see the CX5 and CX1 sensor size comparison.
Ricoh CX5 and Ricoh CX1 have the same sensor sizes so they will provide same level of control over the depth of field when used with same focal length and aperture. On the other hand, since Ricoh CX1 has 11% larger pixel area (3.13µm2 vs 2.81µm2) compared to Ricoh CX5, it has larger pixel area to collect light hence potential to have less noise in low light / High ISO images.