Radian Triad Ultra Quadband Filter

The Triad Ultra filter stands alone in its class as a filter with four ultra-narrow bandpasses that cover Hydrogen alpha, Hydrogen beta, Sulfur II, and Oxygen III wavelengths - the four most common wavelengths for narrowband astrophotography. As a multi-narrowband filter, the Triad Ultra is designed to photograph emission nebulae, planetary nebulae, and supernova remnants, and excels at doing so from light pollution. However, we recommend you try it from dark skies as well - the narrow bandpasses will give you tighter stars and more pronounced nebulosity.