The Antlia HB-OIII filter has been coated with almost complete optical density (OD4) at wavelengths, the filter's cut-off wavelength is 300-1000nm, which meets the spectral requirements of astronomical cameras. The suppression of the IR range is thus further improved. Compared to visual filters with a cut-off depth of OD3 at 350-750nm, this Antlia filter can darken the sky background better and facilitate deep sky observation and photography of nebulae, star clusters and galaxies.
The HB-OIII filter helps to make faint objects much more visible against the blackened background and allows almost photographic views of the Veil, Dumbbell and Orion nebulae, as well as many other objects - both under light-polluted and dark skies. Since the human eyes are less sensitive at night, large-aperture telescopes are recommended to make the most of this filter visually.
