Both Ricoh GR IIIx and Ricoh GR IIIx HDF have APS-C sized 24.0 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 Ricoh GR IIIx HDF and Ricoh GR IIIx 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 GR IIIx and GR IIIx HDF sensor size comparison.
Sensor Size and Resolution Comparison image of Ricoh GR IIIx and Ricoh GR IIIx HDF Cameras
Ricoh GR IIIx and Ricoh GR IIIx HDF 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.
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
Ricoh GR IIIx
or the
Ricoh GR IIIx HDF ,
including hyperfocal distance.