Both OM System OM-3 and Panasonic GH5 II have Four Thirds sized 20.0 MP resolution sensors so sensor size and resolution is not a differentiator between these two cameras.
Another similarity between these two cameras is that both Panasonic GH5 II and OM System OM-3 sensors lack anti-alias (Low-Pass) filters. 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 GH5 II sensor size comparison.
Sensor Size and Resolution Comparison image of OM System OM-3 and Panasonic GH5 II Cameras
OM System OM-3 and Panasonic GH5 II 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
OM System OM-3
or the
Panasonic GH5 II ,
including hyperfocal distance.
