Radian Telescopes 65mm Triad Ultra Quad-Band Narrowband Filter

  • Shoot in any light polluted area
  • H-beta, OIII, H-alpha, and SII Band Passes
  • Works with any color camera including DSLRs
  • Exceptional narrow-band-luminance filter
  • Triad Ultra Filter: 65 mm square unmounted
  • Usable on telescopes up to f/2.2 speed!
  • Photo Credit: Ross Clark
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  • Regular price $1,995.00
  • $1,596.00
  • You save: $399.00 (20%)

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Radian Telescopes 65mm Triad Ultra Quad-Band Narrowband Filter

The Radian Triad Square filter has now been improved upon! With the Triad Ultra, you now have narrower band-passes, more light pollution reduction, higher contrast, better separation between H-beta and OIII channels, and sensitivity in the Sulfur II emission lines. Like the original Triad filter, the Triad Ultra is designed to work with color cameras but also as a narrow-band-luminance filter for monochrome cameras.

Hydrogen-beta Oxygen III Hydrogen-alpha Sulfur II
FWHM 5nm 4nm 4nm 4nm
Peak Transmission 79% 97% 87% 90%


The Triad Ultra is 100% American made and uses advanced multi-coatings and extreme tolerance glass, to ensure it is always consistent and accurate. Filter thickness is 3 mm.

Below you'll see an incredible image of the Rosette Nebula taken by Jason Guenzel using the Triad Ultra on the super-fast f/2.2 Celestron RASA telescope! 

Jason Guenzel Nebula with RASA and Triad Ultra

This filter is the 65 mm square unmounted selection.



Filter ShapeSquare
Filter Thickness3mm
Filter TypeTriad


  • Triad Ultra Filter: 65 mm square unmounted
  • Filter case