Pentax 645D has a
40.0MP Medium format (44 x 33 mm ) sized CCD sensor and features Prime II processor. On the other hand, Leica S2 has a
38.0MP Medium format (45 x 30 mm ) sized CCD sensor .
Another difference between these two cameras is that Pentax 645D's sensor lacks 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 645D and S2 sensor size comparison.
Sensor Size and Resolution Comparison image of Pentax 645D and Leica S2 Cameras
Pentax 645D and Leica S2 have almost the same sensor size, so neither of them has any significant advantage over the other in terms of providing control over depth of field when used with the same focal length and aperture.
DxOMark Sensor Scores
Both Pentax 645D and Leica S2 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, 645D has scored 82, 6 points higher than S2.
Model
Overall
Color Depth
Dynamic Range
Low-light ISO
Pentax 645D
82
24.6 bits
12.6 Evs
1262 ISO
Leica S2
76
23.9 bits
12.2 Evs
824 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
Pentax 645D
or the
Leica S2 ,
including hyperfocal distance.
