Icon class icon_class fas fa-quote-left icon_class_computed fas fa-quote-left Related content An object infinitely far from the optical system forms an image at the rear focal plane Source Wikipedia Copyright information Text from Wikipedia and Wiktionary web pages quoted for educational purposes is subject to the Wikipedia Creative Commons Attribution ShareAlike Licence Snippet kind INFO Keywords optics principal focus focal point mirror lens spherical mirror parabolic mirror Previous snippet Full quote A principal focus or focal point is a special focus: For a lens, or a spherical or parabolic mirror, it is a point onto which collimated light parallel to the axis is focused. URL https://en.wikipedia.org/wiki/Focus_(optics) Next snippet Related snippets An object infinitely far from the optical system forms an image at the rear focal plane. The front and rear (or back) focal planes are defined as the planes, perpendicular to the optic axis, which pass through the front and rear focal points. If the medium surrounding the optical system has a refractive index of 1 (e.g., air or vacuum), then the distance from the principal planes to their corresponding focal points is just the focal length of the system. Related snippets (backlinks) Visit also Visit also (backlinks) Flags
