Light Pollution Imaging Filter, 11" RASATake beautiful images of deep sky objects from light polluted suburban locations with the Rowe Ackermann Schmidt Astrograph (RASA) using this all new light pollution suppression filter designed by Celestron and Astrodon, the leading astroimaging filter company Custom fit to drop into RASAs optical window, so you get optimum optical performance even with the addition of the filter Selectively removes unwanted light pollution while allowing more overall