<P> In Gaussian optics , the cardinal points consist of three pairs of points located on the optical axis of a rotationally symmetric , focal , optical system . These are the focal points , the principal points , and the nodal points . For ideal systems , the basic imaging properties such as image size , location , and orientation are completely determined by the locations of the cardinal points ; in fact only four points are necessary : the focal points and either the principal or nodal points . The only ideal system that has been achieved in practice is the plane mirror , however the cardinal points are widely used to approximate the behavior of real optical systems . Cardinal points provide a way to analytically simplify a system with many components , allowing the imaging characteristics of the system to be approximately determined with simple calculations . </P>
<P> In Gaussian optics , the cardinal points consist of three pairs of points located on the optical axis of a rotationally symmetric , focal , optical system . These are the focal points , the principal points , and the nodal points . For ideal systems , the basic imaging properties such as image size , location , and orientation are completely determined by the locations of the cardinal points ; in fact only four points are necessary : the focal points and either the principal or nodal points . The only ideal system that has been achieved in practice is the plane mirror , however the cardinal points are widely used to approximate the behavior of real optical systems . Cardinal points provide a way to analytically simplify a system with many components , allowing the imaging characteristics of the system to be approximately determined with simple calculations . </P>
what are cardinal points of a thick lens
what are cardinal points of a thick lens
focal points principal points nodal points
focal points principal points nodal points