Ricoh PX has a
16.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CCD sensor and features Smooth Imaging Engine IV processor. 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 PX and ZS99 sensor size comparison.
Sensor Size and Resolution Comparison image of Ricoh PX and Panasonic ZS99 Cameras
Ricoh PX and Panasonic ZS99 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.
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
Ricoh PX
or the
Panasonic ZS99 ,
including hyperfocal distance.