Watch Vic Maris of Stellarvue, talk filters with Chris of Chroma, at the 247th meeting of AAS: Chroma Filters at AAS
OIII 8nm Narrow Band filters isolate the doublet emission of doubly ionized Oxygen. After ionized hydrogen, this is the next most common emission when imaging nebulae. Doublet emission occurs at 495.9 and 500.7 nm.
