Doming effect in scans & Embedded S vs Mini vs Stereo S


I have an Embedded S in my possesion and I’m quite pleased with it, the readings are quite good, up to 600mm. After that I see a weird doming effect where the scanner seems to try and interpolate between two distinct heights.

All scans are raw pointcloud data of a scan using OpenNI of a part 180mm in diameter 45mm off the ground. Does anybody know why this happens?

I guess I need a scanner that would give me greater scanning distances. The Stereo S is rated for up to 3m, other than that I don’t really see the differences between them. Can someone with experience tell me what differences I would see? Especially accuracy wise. I mainly scan flat shiny metal parts, and every mm of accuracy matters. What scanner would be best between the Embedded, Stereo and Mini? I’d really only want to scan at distances up to 900mm.

Thank you in advance