Panasonic FS42 has a
10.0MP 1/2.5-inch (5.744 x 4.308 mm ) sized CCD sensor . On the other hand, Panasonic FP2 has a
14.0MP 1/2.3-inch (6.08 x 4.56 mm ) sized CCD sensor and features Venus Engine IV processor.
Below you can see the FS42 and FP2 sensor size comparison.
As seen above, Panasonic FP2 has a 1.1x Larger sensor area than Panasonic FS42. 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.