Turning shapes other than cylindrical

[uv8452]

Dear Michael,
you are not an Occasional Machinist - your are a very well co-ordinated hands latheman!
Very effective and straight-to-a-solution reasoning.
What came into my mind while watching: 1. sharp contour drawn with a knife-edge 2mm 4H lead; 2. cross-hair with a loupe; 3.vague thought: shape/contour of insert's edge somehow 'applied' to loupe.
Ulrich