Disclosed is an actuator unit for positioning an optical element, comprising a first reluctance actuator comprising a first stator part and a first mover part separated by a gap in a first direction. The first mover part is constructed and arranged to be connected to the optical element and for moving the optical element. The first stator part is constructed and arranged to exert a magnetic force on the first mover part along a first line of actuation. The first mover part is movable relative to the first stator part in the first direction. The first stator part and the first mover part are constructed and arranged such that the first line of actuation is, in operational use, moving along with the first mover part in a second direction perpendicular to the first direction, for at least a predetermined movement range of the first mover part in the second direction.