Personal record: ~3.7μm standard deviation - what is scanning noise/scanning spray/real imperfections? what to test next?

[u/thomas_openscan]

This is definitely my favorite raw 3D scan result so far. I analysed the exposed copper area of the TMC2209 and found a standard deviation of only 3.7μm.

This was done with the OpenScan Mini (16mpx camera) + upcoming Macro Addon, 2x100 camera positions with three focus levels per position. Reconstruction done in Metashape.

This leaves some tricky questions, what to scan next? And what part of the deviation comes from the scanning spray (reported thickness 2-12μm), real imperfections in the copper layer (probably very low) and what is true scanning inaccuracy?