Nikon S6500 has a
16.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized BSI-CMOS sensor . On the other hand, Pentax I-10 has a
12.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CCD sensor and features Prime processor.
Below you can see the S6500 and I-10 sensor size comparison.
Sensor Size and Resolution Comparison image of Nikon S6500 and Pentax I-10 Cameras
Nikon S6500 and Pentax I-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 Pentax I-10 has 32% larger pixel area (2.34µm 2 vs 1.76µm 2 ) compared to Nikon S6500, it has larger pixel area to collect light hence potential to have less noise in low light / High ISO images.
Sensor size sets the circle of confusion, so it drives how much depth of field each
of these bodies gives you at a given aperture. You can calculate it exactly for the
Nikon S6500
or the
Pentax I-10 ,
including hyperfocal distance.