OM System OM-3 has a
20.0MP Four Thirds (17.4 x 13 mm ) sized Stacked BSI Live MOS Sensor sensor and features TruePic X Dual Quad Core processor. On the other hand, Olympus E-M10 III has a
16.0MP Four Thirds (17.4 x 13 mm ) sized CMOS sensor and features TruePic VIII processor.
Another difference between these two cameras is that OM System OM-3's sensor lacks anti-alias (Low-Pass) filter. Removing anti-alias filter increases the sharpness and level of detail but at the same time, it increases the chance of moiré occurring in certain scenes.
Below you can see the OM-3 and E-M10 III sensor size comparison.
Sensor Size and Resolution Comparison image of OM System OM-3 and Olympus E-M10 III Cameras
OM System OM-3 and Olympus E-M10 III 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 Olympus E-M10 III has 26% larger pixel area (14.20µm 2 vs 11.22µm 2 ) compared to OM System OM-3, it has larger pixel area to collect light hence potential to 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
OM System OM-3
or the
Olympus E-M10 III ,
including hyperfocal distance.
