Both Panasonic GH2 and Fujifilm F660EXR have 16.0 MP resolution sensors but Panasonic GH2's sensor is Four Thirds (17.3 x 13 mm ) and Fujifilm F660EXR's sensor is 1/2-inch (6.4 x 4.8 mm ).
Since Panasonic GH2'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 Fujifilm F660EXR.
Below you can see the GH2 and F660EXR sensor size comparison.
Sensor Size and Resolution Comparison image of Panasonic GH2 and Fujifilm F660EXR Cameras
As seen above, Panasonic GH2 has a 7.3x Larger sensor area than Fujifilm F660EXR. 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.
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 GH2
or the
Fujifilm F660EXR ,
including hyperfocal distance.
One thing to watch when comparing these two: they have different sensor sizes
(Four Thirds versus 1/2-inch),
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.