Ricoh GXR S10 24-72mm has a
10.0MP 1/1.7-inch (7.44 x 5.58 mm ) sized CCD sensor and features Smooth Imaging Engine IV processor. On the other hand, Nikon P7800 has a
12.0MP 1/1.7-inch (7.44 x 5.58 mm ) sized BSI-CMOS sensor .
Below you can see the GXR S10 24-72mm F2.5-4.4 VC and P7800 sensor size comparison.
Sensor Size and Resolution Comparison image of Ricoh GXR S10 24-72mm and Nikon P7800 Cameras
Ricoh GXR S10 24-72mm and Nikon P7800 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 GXR S10 24-72mm has 20% larger pixel area compared to Nikon P7800, 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 GXR S10 24-72mm
or the
Nikon P7800 ,
including hyperfocal distance.