Abstract: An observation apparatus enabling alternative sighting of two objects (11, 21) placed in two intersection planes (1, 2). The apparatus comprises, in front of its objective lens (42), a reflector (6) comprising a single flat reflecting surface capable of pivoting around the optical axis (41) of the objective, this axis being positioned substantially in the bisector plane (5) or a plane parallel to the bisector plane of the dihedron formed by the two object planes (1, 2) while forming a specified angle with a ridge (3) of the dihedron. The apparatus applies particularly to an audiovisual device for sighting, using a camera, a person or a document placed before him or her so as to be readable in a normal fashion.