Aberrations

A lens is a device for either concentrating or diverging light, usually produced from a piece of shaped glass. Lenses do not form perfect images, and there is always some degree of distortion or aberration introduced by the lens which causes the image to be an defective replica of the object. Careful design of the lens system for a exacting application ensures that the aberration is minimized. There are several different types of aberration which can influence image quality.