A broadband filter, on the other hand, such as RGB filters from an ... The nature and benefit of narrow band emissions is that they are extremely narrow,Common practical combinations are LRGB, LRGBHa, HaSIIOIII and RGB. ... Baader, Astronomik and Astrodon are ... a light pollution filter (used in unfavorable conditions) in addition to a narrowband set comprising of Hα, SII, OII wavelengths.