Nikon L21 has a
8.0MP 1/2.3-inch (6.08 x 4.56 mm ) sized CCD sensor and features Expeed C2 processor. On the other hand, Panasonic ZS50 has a
12.0MP (1/2. ) sized CMOS sensor .
Below you can see the L21 and ZS50 sensor size comparison.
As seen above, Nikon L21 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.