Nikon Df has a 16.0MP Full frame (36 x 23.9 mm ) sized CMOS sensor and features Expeed 3 processor. You can shoot at maximum resolution of 4928 x 3280 pixels with aspect ratios of and 3:2. Df has a native ISO range of 100 - 12800 which can be boosted to 50 - 204800 and it can save files in RAW format which gives you a wider room for post processing.
Nikon Df is not the highest resolution Full frame camera. Blackmagic PYXIS 12K with its 98.8MP sensor is leading in this class. Check the comparison of Nikon Df vs Blackmagic PYXIS 12K or take a look at Highest resolution DSLR cameras list.
Nikon Df DxOMark Sensor Scores
DxOMark is a benchmark that scientifically assesses image quality of camera sensors. Nikon Df sensor has been tested by DxO Mark and got an overall score of 89 for its image quality. You can find the details of their analysis of Nikon Df here.
Let's look at how the size of the Nikon Df's Full frame sensor compares with other standard sensor sizes.
Comparison image of Nikon Df Sensor Size with other standard sensors
Sensor size is what determines the circle of confusion, and therefore how much
depth of field Nikon Df gives you at any given aperture.
You can
calculate
the exact depth of field for the Nikon Df
at any focal length, aperture and subject distance, including the hyperfocal distance
for landscapes and the very shallow focus zone you get with long telephoto lenses.