Both Panasonic GH4 and Sony A35 have 16.0 MP resolution sensors but Panasonic GH4's sensor is Four Thirds (17.3 x 13 mm ) and Sony A35's sensor is APS-C (23.5 x 15.6 mm ).
Since Sony A35'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 GH4 and A35 sensor size comparison.
Sensor Size and Resolution Comparison image of Panasonic GH4 and Sony A35 Cameras
As seen above, Sony A35 has a 1.6x 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
At Camera Decision, we also look at Dxo Mark sensors when available as we think it is a good indicator of image quality.
Model
Overall
Color Depth
Dynamic Range
Low-light ISO
Panasonic GH4
74
23.2 bits
12.8 Evs
791 ISO
Sony A35
74
23.3 bits
12.7 Evs
763 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
Panasonic GH4
or the
Sony A35 ,
including hyperfocal distance.
One thing to watch when comparing these two: they have different sensor sizes
(Four Thirds 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.
