Editing Objective (optics) (section)

{{Short description|Lens or mirror in optical instruments}}
[[Image:Loupe-binoculaire-p1030891.jpg|thumb|right|Several objective lenses on a microscope.]]
[[File:Binocular 20101111 b.jpg|thumb|Objective lenses of binoculars]]
In [[optical engineering]], an '''objective''' is an optical element that gathers light from an object being observed and [[Focus (optics)|focuses]] the [[ray (optics)|light rays]] from it to produce a [[real image]] of the object. Objectives can be a single [[Lens (optics)|lens]] or [[mirror]], or combinations of several optical elements. They are used in [[microscope]]s, [[binoculars]], [[telescope]]s, [[camera]]s, [[slide projector]]s, [[CD player]]s and many other optical instruments. Objectives are also called '''object lenses''', '''object glasses''', or '''objective glasses'''.