An instrument and technique have been developed for measuring the numerical aperture of a microscope objective to a typical accuracy of 0.0001 compared with about 0.01 for a traditional commercial apertometer.
© 1967 Optical Society of America
Original Manuscript: February 3, 1967
Published: October 1, 1967
P. D. Carman, "A Precise Apertometer," Appl. Opt. 6, 1679-1681 (1967)