There is provided a method that includes projecting a collimated light beam from an optical system to a plane during a first mode of operation of the optical system, and projecting a convergent light beam from the optical system to the plane during a second mode of operation of the optical system. The method further includes, (a) during the first mode of operation, controlling a trajectory of a first light bundle in a first light path in the optical system, to steer the collimated light beam through the plane at a designated incidence angle, and (b) during the second mode of operation, controlling a trajectory of a second light bundle in a second light path of the optical system, to steer the convergent light beam to a target position in the plane. There is also provided an apparatus and a system that employs the method.