Abstract: System and method for estimating and correcting an aberration of an optical system. The method includes capturing a first plurality of images on a first plurality of planes. The first plurality of images is formed by at least the optical system. Additionally, the method includes processing at least information associated with the first plurality of images, and determining a first auxiliary function based upon at least the information associated with the first plurality of images. The first auxiliary function represents a first aberration of the optical system. Moreover, the method includes adjusting the optical system based upon at least information associated with the first auxiliary function.

Abstract: A method is provided for reducing the piston of neighboring first and second surfaces illuminated by polychromatic light transmitted from an unresolved-light source such that light transmitted or reflected from the first surface is out of phase with light respectively transmitted or reflected from the second surface, and the out-of-phase light is passed through a grism that generates a fringe pattern in the far-field. According to one exemplary embodiment, the method includes Fourier transforming the fringe pattern to generate a two-dimensional (2D) power spectrum; generating the absolute value of the 2D power spectrum to form an absolute value representation; displaying the 2D the absolute value representation on a computer display; and reducing the piston to affect rotation of the absolute value representation on the computer display and approximately align a central axis of the absolute value representation with an axis that indicates approximate alignment of the first and second surfaces.