Panasonic ZS3 has a
10.0MP 1/2.3-inch (6.08 x 4.56 mm ) sized CCD sensor . On the other hand, FujiFilm JZ300 has a
12.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CCD sensor .
Below you can see the ZS3 and JZ300 sensor size comparison.
Sensor Size and Resolution Comparison image of Panasonic ZS3 and FujiFilm JZ300 Cameras
Panasonic ZS3 and FujiFilm JZ300 have almost the same sensor size, so neither of them has any significant advantage over the other in terms of providing control over depth of field when used with the same focal length and aperture.
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
Panasonic ZS3
or the
FujiFilm JZ300 ,
including hyperfocal distance.