Olympus E-M1X has a
20.0MP Four Thirds (17.4 x 13 mm ) sized CMOS sensor and features Dual TruePic VIII processor. On the other hand, Panasonic GX7 has a
16.0MP Four Thirds (17.3 x 13 mm ) sized CMOS sensor and features Venus Engine processor.
Below you can see the E-M1X and GX7 sensor size comparison.
Sensor Size and Resolution Comparison image of Olympus E-M1X and Panasonic GX7 Cameras
Olympus E-M1X and Panasonic GX7 have almost the same sensor size, so neither of them has any significant advantage over the other in terms of providing control over depth of field when used with the 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
Olympus E-M1X
or the
Panasonic GX7 ,
including hyperfocal distance.