Kodak C140 has a
8.0MP 1/2.5-inch (5.744 x 4.308 mm ) sized CCD sensor . On the other hand, Nikon S5100 has a
12.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CCD sensor and features Expeed C2 processor.
Below you can see the C140 and S5100 sensor size comparison.
As seen above, Nikon S5100 has a 1.1x Larger sensor area than Kodak C140. 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.