Panasonic LX3 has a
10.0MP 1/1.63-inch (8.07 x 5.56 mm ) sized CCD sensor . On the other hand, Panasonic FS25 has a
12.0MP 1/2.3-inch (6.08 x 4.56 mm ) sized CCD sensor .
Below you can see the LX3 and FS25 sensor size comparison.
As seen above, Panasonic LX3 has a 1.6x Larger sensor area than Panasonic FS25. 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.