As the iterating still goes on as I am fixing very minor issues, I use the last iteration to perform some test scans.
For this one, I've scanned a compressor wheel with 150 photos and the 8mpx pi camera. The only post-processing done was cropping the base and reducing the mesh from 6.9M to ~10k polygons. Rendering was done in Blender
You can see and download the high-res model here: https://skfb.ly/6UpVJ
Here is one of the photos from the set:
You can clearly see the uniform chalk layer, which is absolutely necessary to scan such a part. Furthermore I've used the pi-ringlight and a diffuser and polarizer in order to get uniform and reflection-free lighting.