A shield for use with a detector includes a first opening adjacent the detector, a second opening opposite the first opening along an optical axis intersecting the detector, and a field of view defined by the detector and the second opening. A shield body includes alternating curved profile regions and linear profile regions coaxially aligned along the optical axis. The curved profile regions have respective curved interior surfaces concave facing toward the second opening, and the linear profile regions have respective interior surfaces facing toward the first opening. In this way, specular reflections associated with stray light may be greatly reduced.