A lighting device comprising: a plurality of solid state lighting elements arranged in a ring-shaped geometry having a first central axis of symmetry ; an optical element comprising a ring-shaped collimating structure configured to collimate light emitted by the plurality of solid state lighting elements , the ring-shaped collimating structure having a second central axis of symmetry , wherein the optical element is arranged in relation to the plurality of solid state lighting elements such that the first and second central axis of symmetry coincides; and light-mixing optics configured to mix light emitted by the plurality of solid state lighting elements , wherein the light-mixing optics comprises a microlens array comprising a plurality of lenslets arranged at least on the exit surface opposite to the ring-shaped collimating structure , wherein the optical element is arranged such that a focus of a segment of the optical element , thereby forming a ring-shape focus, is in the radial direction on a nearest portion of the plurality of solid-state lighting elements arranged in a ring-shaped geometry, characterized in that the lenslets are elliptical and each has a smaller radius of curvature along the tangential direction of the ring-shaped collimating structure than in the radial direction of the ring-shaped collimating structure , or in that the lenslets are circular and are arranged with a closer spacing in the radial direction of the ring-shaped collimating structure than in the tangential direction of the ring-shaped collimating structure , said light-mixing optics being configured to apply a different degree of light-mixing in a tangential direction of the ring-shaped collimating structure than in a radial direction of the ring-shaped collimating structure . a plurality of solid state lighting elements arranged in a ring-shaped geometry having a first central axis of symmetry ; an optical element comprising a ring-shaped collimating structure configured to collimate light emitted by the plurality of solid state lighting elements , the ring-shaped collimating structure having a second central axis of symmetry , wherein the optical element is arranged in relation to the plurality of solid state lighting elements such that the first and second central axis of symmetry coincides; and light-mixing optics configured to mix light emitted by the plurality of solid state lighting elements , wherein the light-mixing optics comprises a microlens array comprising a plurality of lenslets arranged at least on the exit surface opposite to the ring-shaped collimating structure , wherein the optical element is arranged such that a focus of a segment of the optical element , thereby forming a ring-shape focus, is in the radial direction on a nearest portion of the plurality of solid-state lighting elements arranged in a ring-shaped geometry, characterized in that the lenslets are elliptical and each has a smaller radius of curvature along the tangential direction of the ring-shaped collimating structure than in the radial direction of the ring-shaped collimating structure , or in that the lenslets are circular and are arranged with a closer spacing in the radial direction of the ring-shaped collimating structure than in the tangential direction of the ring-shaped collimating structure , said light-mixing optics being configured to apply a different degree of light-mixing in a tangential direction of the ring-shaped collimating structure than in a radial direction of the ring-shaped collimating structure . <EOS>