Pentax P70 has a
12.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CCD sensor . On the other hand, Panasonic GH3 has a
16.0MP Four Thirds (17.3 x 13 mm ) sized CMOS sensor and features Venus Engine VII FHD processor.
Below you can see the P70 and GH3 sensor size comparison.
Sensor Size and Resolution Comparison image of Pentax P70 and Panasonic GH3 Cameras
As seen above, Panasonic GH3 has a 8.0x 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
Panasonic GH3 ,
including hyperfocal distance.
One thing to watch when comparing these two: they have different sensor sizes
(1/2.3-inch versus Four Thirds),
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.
