Panasonic FZ47 has a
12.0MP 1/2.3-inch (6.08 x 4.56 mm ) sized CCD sensor and features Venus Engine FHD processor. On the other hand, Panasonic LZ20 has a
16.0MP 1/2.3-inch (6.08 x 4.56 mm ) sized CCD sensor .
Below you can see the FZ47 and LZ20 sensor size comparison.
Panasonic FZ47 and Panasonic LZ20 have the same sensor sizes so they will provide same level of control over the depth of field when used with same focal length and aperture. On the other hand, since Panasonic FZ47 has 32% larger pixel area compared to Panasonic LZ20, it has potential to collect more light on pixel level hence have less noise in low light / High ISO images.