Kodak Z915 has a
10.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CCD sensor . On the other hand, Panasonic ZS50 has a
12.0MP (1/2. ) sized CMOS sensor .
Below you can see the Z915 and ZS50 sensor size comparison.
As seen above, Kodak Z915 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.