Casio EX-Z35 has a
12.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CCD sensor and features Exilim Engine 5.0 processor. On the other hand, Casio EX-ZS15 has a
14.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CCD sensor .
Below you can see the EX-Z35 and EX-ZS15 sensor size comparison.
Casio EX-Z35 and Casio EX-ZS15 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.