Time and time again Baader were made aware of customers who were combining our Neodymium Moon and Skyglow filter with our Fringe Killers to deliver amazingly colour-corrected images to achromatic refractors. This combination however did produce refelctions.
After analysing these reports Baader developed the Baader Semi-APO filter with IR blocker, a reflection-free combination of the Moon & Skyglow with a stronger coating of the Fringe killer. This result was a virtually colour-neutral image without the blue and red halos (violet fringing) and an increase to image contrast.