Radian Telescopes 65mm Triad Ultra Quad-Band Narrowband Filter

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.

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.

Since the filter has extremely narrow band passes, telescopes with focal ratios faster than f/4 will move transmission off band. Telescopes with focal ratios between f/2.9 and f/3.9 are compatible with Triad Ultra, with lower transmissions. Between f/2.2 and f/2.8 will have about 0.8 nm band-shift.

Choose between the 2-inch threaded, 50 mm unmounted, 65 mm square unmounted, or 52 mm photographic thread filter sizes.

This filter is the 65 mm square unmounted selection.