A light projector is provided which includes an elliptical reflector, a
first spherical retro-reflector, the first retro-reflector having an
first aperture formed therein, the first aperture having a first diameter
and a first center-point, a second spherical retro-reflector located
between the elliptical reflector and the first retro-reflector, the
second retro-reflector having a second aperture formed therein, the
second aperture having a second diameter and a second center-point, the
second diameter smaller than the first diameter, the first and second
center-points lying along a common axis, and a light source, the light
source located at a foci of the elliptical reflector, the light source
lying along the common axis, the elliptical reflector reflecting light
emitted by the light source, the reflected light passing through the
first and second apertures, the first and second retro-reflectors being
positioned so as to reflect light emitted by the light source back
towards the light source. Also provided is a light projector that
includes a light source projecting a beam of light; and an optical
element movable between a first position in which the beam of light does
not impinge upon the optical element, a second position in which
substantially all of the beam of light impinges upon the optical element,
and a plurality of intermediate positions in which a portion of the beam
of light impinges upon the optical element, wherein the optical element
is comprised of a plurality of radially sectioned sub-elements.