The Optolong L-Pro Light pollution filter is a multi-bandpass filter optimized for various emission spectra in reflection nebulae and galaxies, and to remove multiple common artificial light sources as well (such as Mercury or Sodium vapor lamps). It comes in various form factors for individual camera use, or telescope use, including a 2″ and 1.25″ form factor. It contains Continue reading “The Optolong L-Pro 2″ Light Pollution Filter”