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Using the LSA fan

The LSA (Longitudinal Spherical Aberration) is a plot of focal distance versus pupil coordinate that allows you to judge the zonal contribution to spherical aberration.

To open the LSA window:

  1. Select from the menu Analysis > Fans > Longitudinal

The LSA is displayed as a function of the normalized pupil coordinate. A tangential scan is made, using the y radius of the entrance pupil. The options button will summon a utility window that will let you change the number of points at which the LSA is calculated.

See also