Both Sony HX10V and Sony HX99 have 18.0 MP resolution sensors but Sony HX10V's sensor is 1/2.3-inch (6.17 x 4.55 mm ) and Sony HX99's sensor is (6.17 x 4.55 mm ).
Since Sony HX99's has a larger sensor area with the same resolution, this means that it also has a larger pixel area hence better light collecting capacity for a given aperture compared to Sony HX10V.
Below you can see the HX10V and HX99 sensor size comparison.
Sensor Size and Resolution Comparison image of Sony HX10V and Sony HX99 Cameras
Sony HX10V and Sony HX99 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.
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
Sony HX10V
or the
Sony HX99 ,
including hyperfocal distance.
One thing to watch when comparing these two: they have different sensor sizes
(1/2.3-inch versus ),
so compare them at the same framing rather than the same focal length.
Put the same focal length on the smaller sensor and it will show less depth of
field, not more, because it also crops tighter. The calculator shows the
full frame equivalent focal length for each body so you can match the framing.