Patent ID: 7098433

Claim:
An optical system deviation estimating apparatus for measuring wavefront propagating through space after having passed through an optical system under test for thereby estimating deviation quantities of optic disposition in said optical system under test on the basis of the measured wavefront, characterized in that said apparatus comprises a) an erected/inverted attitude setting device for changing dispositional attitude of said optical system under test in order to reduce an aberration in the measured wavefront, b) a non-interferometric type wavefront measuring device for measuring wavefronts, respectively, at the attitudes of said optical system as set up without making use of interference phenomenon of light, c) a polynomial approximation device for expanding measured wavefront values determined by said non-interferometric type wavefront measuring device to a polynomial, d) an averaging arithmetic device for averaging the measured values derived from output of said non-interferometric type wavefront measuring device or alternatively arithmetic values derived from output of said polynomial approximation device, and e) a polynomial specific coefficient extraction arithmetic device for extracting specific coefficient values of said polynomial, characterized in that said averaging arithmetic device is designed for summing and averaging the wavefront values measured, respectively, in the erected attitude state and the inverted attitude state set up relative to the direction of gravity with the aid of said erected/inverted attitude setting means.