Pentax WS80 has a
10.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CCD sensor and features Prime processor. On the other hand, Ricoh WG-8 has a
20.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized BSI-CMOS sensor .
Ricoh WG-8's sensor provides 10MP more than Pentax WS80's sensor, which gives a significant advantage in real life. You can print your images larger or crop more freely.
On the other hand, please keep in mind that Max sensor resolution is not the only determinant of resolving power. Factors such as the optical elements, low pass filter, pixel size and sensor technology also affects the final resolution of the captured image.
Below you can see the WS80 and WG-8 sensor size comparison.
Sensor Size and Resolution Comparison image of Pentax WS80 and Ricoh WG-8 Cameras
Pentax WS80 and Ricoh WG-8 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 WS80 has 102% larger pixel area compared to Ricoh WG-8, it has potential to collect more light on pixel level hence 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
Pentax WS80
or the
Ricoh WG-8 ,
including hyperfocal distance.