Astro Duo-Narrowband (Duo-NB) Filter

Astrophotography is all about capturing light from billions of years ago. As avid astrophotographers, the STC team thought long and hard about how to create a filter to capture ultra-high contrast nebulae images - even with urban light pollution.

STC is the FIRST company in the world to create a dual-narrowband pass in ONE filter for deep sky astrophotographers. As experienced astrophotographers painfully know, shooting multiple images using two different filters would be necessary. Our Duo-Narrowband filter cuts the time required in half!  Many have tried to copy our technology. None are successful in delivering our level of optical quality!

STC’s Astro Duo-Narrowband filter is specifically engineered to capture 7-12nm bandpass for H-Alpha, and Oxygen III nebula emission lines found in gaseous nebulae. With a transmission rating of greater than 85%, this is an astrophotographers' dream filter. 



  • Blocks urban light pollution. We coat the filter using an ion beam-assisted deposition (IBAD). 
  • 1mm Schott B270 optical glass prevents fogging by quickly absorbing and dissipating heat.
  • Double-sided anti-smudge nano-coating is hydrophobic stopping moisture and mold.
  • Anti-static coating keeps dust and fibers away.
  • Super flat surface so you can capture clear images even when shooting at 8K and with 1200mm high-magnification telescope lens.
  • Anodized aluminum eliminates surface reflection to avoid glare and ghost images. 
  • Aluminum rim treated with Teflon and black matte finish and easy to remove.
  • Can be used with STC’s Astro-AdapterM48-M56 astronomical lens adapterring, 0.75mm Pitch (sold separately).
  • Covered by the world’s first global filter warranty and repair service. 

About This Product


  • Recommended for use with telephoto lenses of focal length 60mm and greater. For wider than 60mm check out our clip filters
  • For wide-angle lenses, you could try our clip filters. (recommended for focal length 14mm (full-frame) and above).