Panasonic ZS50 has a
12.0MP (1/2. ) sized CMOS sensor . On the other hand, Olympus SZ-12 has a
14.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CCD sensor .
Below you can see the ZS50 and SZ-12 sensor size comparison.
As seen above, Olympus SZ-12 has a infx Larger sensor area than Panasonic ZS50. 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.