sine condition

sine condition 

The elimination of distortion and coma in an image is met when

M = n sin u/n′ sin u′ or nh sin u = n′h′ sin u′

where M is the lateral magnification, n and n′ the refractive indices of the media in the object and image space, u and u′ are the angular apertures on the object and image sides, and h and h′ the sizes of the object and image, respectively. Syn. Abbé's condition. See angular aperture; coma; correction; distortion.

Millodot: Dictionary of Optometry and Visual Science, 7th edition. © 2009 Butterworth-Heinemann