Astrodon 20 nm Filters – H-α 20nm (Close-Out)

Astrodon 20 nm Filters – H-α 20nm (Close-Out)


H-α (hydrogen-alpha) at 656 nm (nanometers) is deep red in color and the most popular narrowband filter, and this 20nm H-α is the same formulation but in a wider bandpass. Hydrogen is ubiquitous in the cosmos and is present in emission nebula (North American, Pelican), planetary nebula (Dumbbell, Ring), Wolf-Rayet objects (Crescent, Thor’s Helmet) and supernova remnants (Veil). Many imagers like to present just a black-and-white H-α image of an object. It is has a beauty all by itself, like an Ansel Adams photo.




Astrodon Hydrogen Alpha 20 nm filters are formulated just like our narrowband hydrogen alpha filters, but with a wider band pass.

Step up to the quality and performance of Astrodon filters.


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Tutorials by Astrodon’s founder, Don Goldman


Astrodon Narrowband Presentation