Panasonic GH1 has a
12.0MP Four Thirds (18.89 x 14.48 mm ) sized CMOS sensor and features Venus Engine HD processor. On the other hand, Panasonic GF7 has a
16.0MP Four Thirds (17.3 x 13 mm ) sized CMOS sensor and features Venus Engine processor.
Below you can see the GH1 and GF7 sensor size comparison.
Sensor Size and Resolution Comparison image of Panasonic GH1 and Panasonic GF7 Cameras
As seen above, Panasonic GH1 has a 1.2x Larger sensor area than Panasonic GF7. 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 GH1
or the
Panasonic GF7 ,
including hyperfocal distance.