Panasonic ZS40 has a
18.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CMOS sensor and features Venus Engine processor. On the other hand, Olympus SZ-10 has a
14.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CCD sensor and features TruePic III+ processor.
Below you can see the ZS40 and SZ-10 sensor size comparison.
Panasonic ZS40 and Olympus SZ-10 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 Olympus SZ-10 has 30% larger pixel area (2.04µm2 vs 1.56µm2) compared to Panasonic ZS40, it has larger pixel area to collect light hence potential to have less noise in low light / High ISO images.