Ricoh GR Digital III has a
10.0MP 1/1.7-inch (7.44 x 5.58 mm ) sized CCD sensor and features GR engine III processor. On the other hand, Nikon P340 has a
12.0MP 1/1.7-inch (7.44 x 5.58 mm ) sized BSI-CMOS sensor .
Below you can see the GR Digital III and P340 sensor size comparison.
Sensor Size and Resolution Comparison image of Ricoh GR Digital III and Nikon P340 Cameras
Ricoh GR Digital III and Nikon P340 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 Ricoh GR Digital III has 20% larger pixel area compared to Nikon P340, 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
Ricoh GR Digital III
or the
Nikon P340 ,
including hyperfocal distance.