We used a LED in a Ronchi tester to obtain two main improvements: (i) We can choose one of two wavelength bands to illuminate and record the ronchigram, and (ii) we can change the irradiance of the illumination source according to the optical system under test and the detector array. This can be done by use of an adequate electronic circuit.
© 2001 Optical Society of America
Juan Manuel Nuñez-Alfonso, Alberto Cordero-Dávila, S. Vergara-Limon, and J. Cuautle-Cortes, "Improved Ronchi Tester," Appl. Opt. 40, 501-505 (2001)