Before revision: It is much faster to set up than the standard Foucault test but, unlike the Foucault tester, the Ronchi test requires a piece of specialized equipment (the Ronchi grating) and is more subjective.
After revision: It is much faster to set up than the standard Foucault Knife Edge Test but, unlike the Foucault tester, the Ronchi test requires a piece of specialized equipment (the Ronchi grating) and is more subjective.