Kodak FZ55 has a
16.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CMOS sensor . On the other hand, Pentax P70 has a
12.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CCD sensor .
Below you can see the FZ55 and P70 sensor size comparison.
Sensor Size and Resolution Comparison image of Kodak FZ55 and Pentax P70 Cameras
Kodak FZ55 and Pentax P70 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 P70 has 32% larger pixel area (2.34µm 2 vs 1.76µm 2 ) compared to Kodak FZ55, 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
Kodak FZ55
or the
Pentax P70 ,
including hyperfocal distance.