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Radian Telescopes 65mm Triad Ultra Quad-Band Narrowband Filter


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  • 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

Product Details

  • 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.


  • specifications

    Filter ShapeSquare
    Filter Thickness3mm
    Filter TypeLight Pollution/City Light Suppression
    Filter TypeTriad
    Free ShippingYes
  • included items

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

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