Pentax K-5 IIs has a
16.0MP APS-C (23.7 x 15.7 mm ) sized CMOS sensor and features Prime II processor. On the other hand, Olympus E-P2 has a
12.0MP Four Thirds (17.3 x 13 mm ) sized CMOS sensor and features TruePic V processor.
Another difference between these two cameras is that Pentax K-5 IIs'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 K-5 IIs and E-P2 sensor size comparison.
Sensor Size and Resolution Comparison image of Pentax K-5 IIs and Olympus E-P2 Cameras
As seen above, Pentax K-5 IIs has a 1.7x Larger sensor area than Olympus E-P2. 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 Pentax K-5 IIs and Olympus E-P2 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, K-5 IIs has scored 82, 26 points higher than E-P2.
Model
Overall
Color Depth
Dynamic Range
Low-light ISO
Pentax K-5 IIs
82
23.9 bits
14.1 Evs
1208 ISO
Olympus E-P2
56
21.5 bits
10.4 Evs
505 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 K-5 IIs
or the
Olympus E-P2 ,
including hyperfocal distance.
One thing to watch when comparing these two: they have different sensor sizes
(APS-C versus Four Thirds),
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.
