Adjusting camera focus improve scan quality.

Hi.
I'm new to 3d scan, BYOP kit received 3 days ago. Test and try is only time consumming, so I've probably already made 30-40 scans and 20-30 calibrations !
At beginning I found calibration difficult, mostly due to the poor image quality. I made some scans, good, bad, ugly and even strange when calibration fail or laser rotate unatendly. At least I was quite satisfied and have a lote to learn/understand

The image quality bothered me greatly, so I decided to adjust the focus. A bit of googling said that it have already been done successfully. I decided to work on my camera, realy carrefully with my fat fingers holding and forcing a small and fragile part. It was a success, the glu break and the objective was still operationnal (tried another camera, no glu, easier, only need a small amount of force applied with nails).
I made some test with raspivid /raspistill to adust the focus to 10-15inches, before reinserting the camera in it's support.

The quality is way better, as sample pics of a square before and after.

Now, I've to understand software parameters (laser width, threshold,...) for the best result and learning meshlab to get a usable stl !

A sample with a printed part, I could have an idea about layers in the scan.

The model on the plate.

A close-up of the screw part with an external camera.

A close-up of the preview screen.

Layers are here, but I don't know if it's good for the work with meshlab ?

[edit]
I discover lately a post from "FaanP" with the same advice on re-focusing and understand how some scans that I've seen looked so good.