FujiFilm Finepix Z90 has a
14.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CCD sensor . On the other hand, Fujifilm JZ200 has a
16.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CCD sensor .
Below you can see the Finepix Z90 and JZ200 sensor size comparison.
FujiFilm Finepix Z90 and Fujifilm JZ200 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 FujiFilm Finepix Z90 has 6% larger pixel area compared to Fujifilm JZ200, it has potential to collect more light on pixel level hence have less noise in low light / High ISO images.