In the summer of 1969, R. L. Gregory was working at Bell Labs, and suggested one might be able to increase the effective depth of field of a microscope if, instead of making the objective achromatic, one arranged that the different spectral colors come to foci at different distances from the lens. J. S. Courtney-Pratt suggested that one might then be able to view the image in 3-D by use of a simple binocular eyepiece modified to give a convergence of the images that varied with the spectral color. A 16-mm NA 0.4 objective has been made that gives a lateral resolution of 1 μ and a depth of field of 100 μ. 3-D displays present sharp images of objects with dark field illumination with depth magnification at any chosen value up to ± 10,000×.
© 1973 Optical Society of America
Original Manuscript: December 21, 1972
Published: October 1, 1973
J. S. Courtney-Pratt and R. L. Gregory, "Microscope with Enhanced Depth of Field and 3–D Capability," Appl. Opt. 12, 2509-2519 (1973)