Nikon Df has a
16.0MP Full frame (36 x 23.9 mm ) sized CMOS sensor and features Expeed 3 processor. On the other hand, Pentax K20D has a
15.0MP APS-C (23.4 x 15.6 mm ) sized CMOS sensor .
Below you can see the Df and K20D sensor size comparison.
Sensor Size and Resolution Comparison image of Nikon Df and Pentax K20D Cameras
As seen above, Nikon Df has a 2.4x Larger sensor area than Pentax K20D. Larger sensors give photographer more control on the depth of field and blurry background compared to smaller sensor when shot in same focal length and aperture.
DxOMark Sensor Scores
Both Nikon Df and Pentax K20D sensors have been tested by DxoMark. DxoMark scores camera sensors for color depth (DXO Portrait), dynamic range (DXO Landscape) and low-light sensitivity (DXO Sports), and also gives them an overall score. Of the two cameras that we are comparing, Df has scored 89, 24 points higher than K20D.
Model
Overall
Color Depth
Dynamic Range
Low-light ISO
Nikon Df
89
24.6 bits
13.1 Evs
3279 ISO
Pentax K20D
65
22.9 bits
11.1 Evs
639 ISO
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
Nikon Df
or the
Pentax K20D ,
including hyperfocal distance.
One thing to watch when comparing these two: they have different sensor sizes
(Full frame versus APS-C),
so compare them at the same framing rather than the same focal length.
Put the same focal length on the smaller sensor and it will show less depth of
field, not more, because it also crops tighter. The calculator shows the
full frame equivalent focal length for each body so you can match the framing.
