variation in focal length of a lens or mirror from center to edge, due to its spherical shape.
(physics) a defect of optical systems that arises when light striking a mirror or lens near its edge is focused at different points on the axis to the light striking near the centre. The effect occurs when the mirror or lens has spherical surfaces See also aberration (sense 4)
spherical aberration n.
A blurred image that occurs when light from the margin of a lens or mirror with a spherical surface comes to a shorter focus than light from the central portion. Also called dioptric aberration.
See under aberration.
noun, Geometry. 1. an angle formed by arcs of great circles of a sphere. spherical angle noun 1. an angle formed at the intersection of two great circles of a sphere
noun 1. the branch of astronomy dealing with the determination of the positions of celestial bodies on the celestial sphere.
noun, Mathematics. 1. Usually, spherical coordinates. any of three coordinates used to locate a point in space by the length of its radius vector and the angles this vector makes with two perpendicular polar planes. spherical coordinate Any of a set of coordinates in a three-dimensional system for locating points in space by means of […]
noun, Mathematics. 1. the difference between the sum of the angles of a spherical triangle and two right angles.