Apparatus for converting an optical theodolite into a laser theodolite

Apparatus (4) for converting an optical theodolite (2) into a laser theodolite, which apparatus comprises a laser diode adapter (6) for connection to the optical theodolite in place of an eyepiece of a telescope (8) of the optical theodolite, and driver means (10) for the laser diode adapter (6); the laser diode adapter (6) comprising a housing (12), a laser diode (14); a holographic image reshaping lens (51), and a focusing lens (52) in the housing (12), and an externally threaded male portion (16) for screwing into the telescope (8) in place of the eyepiece; and the driver means (10) having securing means (18) for securing the driver means (10) to the optical theodolite (2) remote from the laser diode adapter (6).