Abstract: A borescope has an inverting dove prism (24) mounted on an ocular mount (12) proximally of an ocular lens (11). The ocular mount is axially adjustable by rotation of a collar (26) to achieve focusing and is rotatable about the axis independently of the focus position in unison with orbital scanning of a reflector (7) at the distal end of the borescope. Location of the dove prism proximally of the ocular lens avoids the need to include an invertor within the optical relay of insertion tube (2) thereby avoiding aperture reduction and simplifying assembly.

Abstract: A method of forming a fibre optic terminal assembly (17) comprising the steps of inserting fibres (8) into a duct (3) defined by a housing (1) comprising a sleeve portion (21) having an open end (10) and defining a tubular portion of the duct, the fibres being inserted such that the fibres are supported in a closely packed bundle throughout the tubular portion and project through the end of the sleeve portion, trimming the bundle to form an end face (11) thereof, and bonding the fibres to one another and to the housing thereby forming a terminal assembly. The fibres are bonded by applying heat locally to the end face to form a molten glass surface layer, allowing glass from the layer to flow between the fibres of the bundle and allowing the glass to cool such that the glass forms a matrix fusing the fibres to one another and to the housing.