An illumination system comprising a light source that emits light of a first sense and a second sense. The illumination system also comprises a collimator that collimates light from the light source along an optical axis and within a maximum angle with respect to the optical axis. The illumination system further comprises a filter that reflects light of the first sense, the filter positioned at an angle other than normal to the optical axis and other than 45 degrees from the optical axis. Further, the illumination system also includes an optical system positioned along the optical axis to accept light that passes through the filter and transmits the portion of the light within the maximum angle.