The diameter of the widest beam of light incident on an optical system that goes to form an image; also in extended use (e.g. in connection with radio waves or particle beams).
Origin
Mid 19th century; earliest use found in Littell's Living Age.
Definition of effective aperture in US English:
effective aperture
noun
Optics
The diameter of the widest beam of light incident on an optical system that goes to form an image; also in extended use (e.g. in connection with radio waves or particle beams).
Origin
Mid 19th century; earliest use found in Littell's Living Age.