Leica S2 has a
38.0MP Medium format (45 x 30 mm ) sized CCD sensor . On the other hand, Pentax K-1 has a
36.0MP Full frame (35.9 x 24 mm ) sized CMOS sensor .
One other difference between these two cameras that is worth mentioning is that Pentax K-1's sensor doesn't have an anti-alias (Low-Pass) filter. Removing anti-alias filter increases the sharpness and level of detail but at the same time, it increases the chance of moiré occurring in certain scenes.
Below you can see the S2 and K-1 sensor size comparison.
Sensor Size and Resolution Comparison image of Leica S2 and Pentax K-1 Cameras
As seen above, Leica S2 has a 1.6x Larger sensor area than Pentax K-1. 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
DxOMark is a benchmark that scientifically assesses image quality of camera sensors. It 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. Leica S2 and Pentax K-1 sensors have been tested by DxO and the results show that K-1 has a better overall score of 96, 20 points higher compared to S2's score of 76.
Model
Overall
Color Depth
Dynamic Range
Low-light ISO
Leica S2
76
23.9 bits
12.2 Evs
824 ISO
Pentax K-1
96
25.4 bits
14.6 Evs
3280 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
Leica S2
or the
Pentax K-1 ,
including hyperfocal distance.
One thing to watch when comparing these two: they have different sensor sizes
(Medium format versus Full frame),
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.
