CXB ExoPlanet-BB (Blue Blocking) Filter – Exoplanet Light Curve PhotometryThe CXB ExoPlanet BB Filter (formerly Astrodon) is a specialized blue blocking filter designed for amateur astronomers measuring exoplanet light curves with backyard telescopes and sensitive CCD CMOS cameras. It blocks ultraviolet and blue light shorter than approximately 500 nm (corresponding to the start of the conventional V band) while transmitting light through the visible spectrum into the near infrared. This provides most of the high signal to