Nikon P90 has a
12.0MP 1/2.3-inch (6.08 x 4.56 mm ) sized CCD sensor . On the other hand, Panasonic FX75 has a
14.0MP 1/2.3-inch (6.08 x 4.56 mm ) sized CCD sensor and features Venus Engine HD II processor.
Below you can see the P90 and FX75 sensor size comparison.
Sensor Size and Resolution Comparison image of Nikon P90 and Panasonic FX75 Cameras
Nikon P90 and Panasonic FX75 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 Nikon P90 has 16% larger pixel area compared to Panasonic FX75, it has potential to collect more light on pixel level hence have less noise in low light / High ISO images.
Sensor size sets the circle of confusion, so it drives how much depth of field each
of these bodies gives you at a given aperture. You can calculate it exactly for the
Nikon P90
or the
Panasonic FX75 ,
including hyperfocal distance.