Baader O-III 8.5nm 50,8mm filter

Together with Baader H-alpha 7nm filter and S-II 8nm filters, the Baader O-III 8.5nm filter enables color imaging using trichromy technique. This filter is also perfect for use with achromatic refractors that, due to chromatic aberration, are not usually recommended for the long-exposure astrophotography. But using this filter the deep-sky astrophotography becomes not only possible but also offers excellent results since the narrow bandwidth virtually delete the effect of chromatic aberration.