Patent attributes
An apparatus is for evaluating optical characteristics of an optical system based on an image forming position of a point image formed through the optical system. The apparatus includes a point image producing unit that forms a point image through the optical system in each point light source; an imaging unit that images the point images to produce a point image distribution image; and a moving unit that changes relative distance between the optical system and the point light source or the imaging unit in an optical axis direction. The apparatus also performs processing of detecting an image forming position in each different relative distance of the point image based on image information of the point image distribution images, the processing including calculating a regression expression for the detected image forming positions to obtain a shape parameter of the image axis in each of the point images.
