Filters

• Enhance imaging of nebulae with your 8” Rowe-Ackermann Schmidt Astrograph (RASA) by blocking light pollution, improving image contrast, and darkening the sky background.
• This filter transmits only the key Hα-Hβ-OIII wavelengths from emission nebulae, providing high contrast that makes them “pop.”
• This filter selectively blocks wavelengths of light from sources of light polluted skies and natural sky glow.
• Unlike similar filters with narrower bandpasses, this filter was engineered specifically to work with RASA’s fast F/2 optics.
• Fits into the 8” RASA’s integrated filter mount, maintaining peak optical performance.
• Optically flat surfaces free of defects, constructed of Schott glass with anti-reflection coatings.

• Enhance your 8” Rowe-Ackermann Schmidt Astrograph (RASA) by blocking light pollution, improving image contrast, and darkening the sky background.
• This filter selectively blocks wavelengths of light from sources of light pollution, such as streetlights, not broad regions of the spectrum.
• Does not block wavelengths associated with emission nebulae, keeping your nebula images bright and detailed.
• Fits into the 8” RASA’s integrated filter mount, maintaining peak optical performance.
• Optically flat surfaces free of defects, constructed of Schott glass with anti-reflection coatings.

• A customizable way to reduce brightness and glare on the brightest celestial objects like the Moon, Venus, and bright double stars
• Adjust the level of light transmission from 1-40% for the best possible view for your specific target and current viewing conditions
• Simple to use—just rotate filter’s lower ring to adjust brightness
• Threads onto any Celestron 1.25” eyepiece

Astrodon Narrowband filters set a new bar of performance and durability for imaging and research.

Astrodon 5nm Narrowband Filters – H-alpha 5nm

H-α (hydrogen-alpha) at 656 nm (nanometers) is deep red in color and the most popular narrowband filter. 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).

• Four great Moon filters in one kit—everything you’ll ever need for optimal views of the lunar surface
• Three neutral density (ND) filters with different levels of light transmission (13%, 25%, and 50%) allow you to choose the perfect filter for your viewing conditions
• Moon & Sky Glow filter provides high contrast views of the lunar surface and enhances observation of deep sky objects from light polluted skies
• Aluminum filter cells provide a rigid, durable housing for the filter glass and are threaded on top and bottom for stacking
• Kit includes a plastic carrying case with Moon map and legend for identifying the most popular lunar features