Abstract: A magnifying imaging optical unit is part of a metrology system for examining objects. The magnifying imaging optical unit has at most four mirrors which image an object field in an object plane into an image field in an image plane. According to one aspect, an entrance pupil of the magnifying imaging optical unit has a boundary shape which deviates from an ellipse and the aspect ratio of which is not equal to 1. In accordance with a further aspect, reflection surfaces of small-area mirrors which are used for guiding imaging light along an imaging beam path deviate from a spherical shape by at most 10 ?m. This results in a magnifying imaging optical unit in which an imaging result which satisfies the stringent requirements of a metrology system results for a given manufacturing outlay.

Abstract: An optical system (10) for use in an underwater environment is proposed, wherein the optical system (10) comprises a housing which delimits an interior (60) of the optical system (10) with respect to the surroundings (50) in water-tight fashion, and a lens (20) with an outer surface (24), wherein the housing comprises a mount (40), wherein the lens (20) is received in the mount (40) in such a way that the outer surface (24) of the lens (20) is in fluid contact with water of the underwater environment when the optical system (10) is situated in the underwater environment, wherein the outer surface (24) of the lens (20) has an arched form, in particular a convex form, preferably a spherical convex form, wherein the lens (20) has a first arched contact face (28), in particular a spherical contact face, and the mount (40) has a second contact face (48), wherein the lens (20) is arranged in the mount (40) in such a way that the first contact face (28) presses against the second contact face (48) when the pressure

Abstract: An optical system (10) for use in an underwater environment is proposed, wherein the optical system (10) comprises a housing which delimits an interior (60) of the optical system (10) with respect to the surroundings (50) in water-tight fashion, and a lens (20) with an outer surface (24), wherein the housing comprises a mount (40), wherein the lens (20) is received in the mount (40) in such a way that the outer surface (24) of the lens (20) is in fluid contact with water of the underwater environment when the optical system (10) is situated in the underwater environment, wherein the outer surface (24) of the lens (20) has an arched form, in particular a convex form, preferably a spherical convex form, wherein the lens (20) has a first arched contact face (28), in particular a spherical contact face, and the mount (40) has a second contact face (48), wherein the lens (20) is arranged in the mount (40) in such a way that the first contact face (28) presses against the second contact face (48) when the pressure

Abstract: A camera, more particularly for recording aerial images from aircraft, comprising a lens and at least one digital, areal image sensor fixed on a carrier element and having a predetermined pixel size, which image sensor has a curvature, more particularly caused by the fixing on the carrier element within a specific tolerance range. The lens at least partly brings about optical compensation of the curvature of the digital areal image sensor.