Foucault knife-edge test - Wikipedia
Foucault knife-edge test - Wikipedia
Berthold Hamburger's Homepage/Foucault Tester
Why do Foucault's pendulums have to be big? - Quora
Going parabolic: The difference between a Ronchi, Foucault, and a
Foucault test: a quantitative evaluation method
Can focault test a F3 mirror? - Page 2 - ATM, Optics and DIY Forum
Parabolizing a Telescope Mirror
3D Printed Knife Edge Tester and Mirror Stand. (WIP) : r
Do You Foucault?
Geometry of Ronchi test with square grid.