paraxial pencil
1optics — /op tiks/, n. (used with a sing. v.) the branch of physical science that deals with the properties and phenomena of both visible and invisible light and with vision. [1605 15; < ML optica < Gk optiká, n. use of neut. pl. of OPTIKÓS; see OPTIC,… …
2Ray (optics) — Ray of light redirects here. For other uses, see Ray of light (disambiguation). In optics, a ray is an idealized narrow beam of light. Rays are used to model the propagation of light through an optical system, by dividing the real light field up… …
3Optical aberration — v · d · e Optical aberration …
4Numerical aperture — The numerical aperture with respect to a point P depends on the half angle θ of the maximum cone of light that can enter or exit the lens. In optics, the numerical aperture (NA) of an optical system is a dimensionless number that characterizes… …
5aberration — aberrational, adj. /ab euh ray sheuhn/, n. 1. the act of departing from the right, normal, or usual course. 2. the act of deviating from the ordinary, usual, or normal type. 3. deviation from truth or moral rectitude. 4. mental irregularity or… …
