Ricoh GR II has a 16.0MP APS-C (23.7 x 15.7 mm ) sized CMOS sensor and features GR Engine V processor. You can shoot at maximum resolution of 4928 x 3264 pixels with aspect ratios of 1:1, 4:3 and 3:2. GR II has a native ISO range of 100 - 25600 and it can save files in RAW format which gives you a wider room for post processing.
Ricoh GR II is not the highest resolution APS-C camera. Fujifilm X-E5 with its 40.0MP sensor is leading in this class. Check the comparison of Ricoh GR II vs Fujifilm X-E5 or take a look at Highest resolution Compact cameras list.
Ricoh GR II DxOMark Sensor Scores
DxOMark is a benchmark that scientifically assesses image quality of camera sensors. Ricoh GR II sensor has been tested by DxO Mark and got an overall score of 80 for its image quality. You can find the details of their analysis of Ricoh GR II here.
Let's look at how the size of the Ricoh GR II's APS-C sensor compares with other standard sensor sizes.
Comparison image of Ricoh GR II Sensor Size with other standard sensors
Sensor size is what determines the circle of confusion, and therefore how much
depth of field Ricoh GR II gives you at any given aperture.
You can
calculate
the exact depth of field for the Ricoh GR II
at any focal length, aperture and subject distance, including the hyperfocal distance
for landscapes and how close you can get before the focus zone becomes too thin.