Both Pentax P70 and Nikon P330 have 12.0 MP resolution sensors but Pentax P70's sensor is 1/2.3-inch (6.17 x 4.55 mm ) and Nikon P330's sensor is 1/1.7-inch (7.44 x 5.58 mm ).
Since Nikon P330'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 Pentax P70.
Below you can see the P70 and P330 sensor size comparison.
Sensor Size and Resolution Comparison image of Pentax P70 and Nikon P330 Cameras
As seen above, Nikon P330 has a 1.5x Larger sensor area than Pentax P70. Larger sensors give photographer more control on the depth of field and blurry background compared to smaller sensor when shot in 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
Pentax P70
or the
Nikon P330 ,
including hyperfocal distance.
One thing to watch when comparing these two: they have different sensor sizes
(1/2.3-inch versus 1/1.7-inch),
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.
