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Astronomik SII 6 nm CCD Filter - 31 mm - SII6-31

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Astronomik SII 6 nm CCD Filter - 31 mm

  • Astronomik's SII 6 nm CCD Filter has been created for the express purpose of CCD astrophotography and is presented in a round 31 mm threaded cell
  • Designed to the highest technical standards to enable the optical performance required for deep sky CCD imaging
  • Allows ionized sulfur (SII) light to pass through while completely cutting off the remainder of the visual spectrum plus IR
  • FWHM bandwidth of nearly 6 nm
  • Optimal for imaging planetary nebulae and supernovae vestiges
  • German-made for superior quality optics!

More About the Astronomik 31 mm SII 6 nm CCD Filter

This 31 mm SII 6 nm CCD Filter from Astronomik is the perfect narrowband filter for CCD astro-imaging. With a smaller FWHM (full width at half maximum) of 6 nm, coupled with a usual 96% transmission, this filter is able to provide a remarkable contrast boost. All undesired wavelengths of light not in the SII line (672 nm) are completely occluded from UV up to the IR. This results in a background that is exceptionally dark. With Astronomik filters, transmission reductions and chromatic aberrations only crop up when extremely bright aperture ratios of 1:2 and above are involved, contrary to filters made by other manufacturers.

Astronomik SII CCD filters enhance the contrast between objects, in this case between objects in the ionized sulfur (SII) emission line and the background sky. Also optimal for combating light pollution, this filter blocks artificial light from sources such as mercury and sodium-vapor street lamps, common light pollution culprits. The supreme quality of the Astronomik SII 6 nm CCD substrate allows you to observe the same razor sharp stars you would typically see from your normal telescope.

Complete occlusion of undesired visible and IR band spectral wavelengths is enabled by this Astronomik 31 mm SII 6 nm CCD Filter. Parfocal with all other filters produced by Astronomik and diffraction limited to maintain your telescope's optical performance. Coatings offer strong protection from scratching as well as the impacts of aging and high humidity. This filter is shipped in a durable plastic filter container of superior quality.

Transmission Specifications

  • 96% transmission in the ionized sulfur (SII) line is typical
  • Offers full obstruction of spurious light from UV up to IR