Nikon S9500 has a
18.0MP 1/2.3-inch (6.16 x 4.62 mm ) sized BSI-CMOS sensor . On the other hand, Panasonic ZS99 has a
20.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized BSI-CMOS sensor and features Venus Engine processor.
Below you can see the S9500 and ZS99 sensor size comparison.
Sensor Size and Resolution Comparison image of Nikon S9500 and Panasonic ZS99 Cameras
Nikon S9500 and Panasonic ZS99 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
Nikon S9500
or the
Panasonic ZS99 ,
including hyperfocal distance.