Tests utilized include the Foucault knife edge and related types such as the Ronchi and its variants as well as interferometery. Tests are used as appropriate to the task. The autocollimation test is used extensively both for the production of parabolic mirrors as well as refractor objectives and the Ritchey-Common test has been used for the manufacture of large flats. 


A Better Method of Measuring Optical Performance

Testing and Certifying in Detail