Both Pentax K-5 II and Panasonic GH4 have 16.0 MP resolution sensors but Pentax K-5 II's sensor is APS-C (23.7 x 15.7 mm ) and Panasonic GH4's sensor is Four Thirds (17.3 x 13 mm ).
Since Pentax K-5 II's has a larger sensor area with the same resolution, this means that it also has a larger pixel area hence better light collecting capacity for a given aperture compared to Panasonic GH4.
Below you can see the K-5 II and GH4 sensor size comparison.
Sensor Size and Resolution Comparison image of Pentax K-5 II and Panasonic GH4 Cameras
As seen above, Pentax K-5 II has a 1.7x Larger sensor area than Panasonic GH4. 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 II and Panasonic GH4 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 II has scored 82, 8 points higher than GH4.
Model
Overall
Color Depth
Dynamic Range
Low-light ISO
Pentax K-5 II
82
23.8 bits
14.1 Evs
1235 ISO
Panasonic GH4
74
23.2 bits
12.8 Evs
791 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 II
or the
Panasonic GH4 ,
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.
