Pentax X90 has a
12.0MP 1/2.3-inch (6.08 x 4.56 mm ) sized CCD sensor and features Prime processor. On the other hand, Pentax RZ18 has a
16.0MP 1/2.3-inch (6.08 x 4.56 mm ) sized CCD sensor .
Below you can see the X90 and RZ18 sensor size comparison.
Sensor Size and Resolution Comparison image of Pentax X90 and Pentax RZ18 Cameras
Pentax X90 and Pentax RZ18 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 Pentax X90 has 32% larger pixel area compared to Pentax RZ18, 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
Pentax X90
or the
Pentax RZ18 ,
including hyperfocal distance.
