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Astronomik SII 12 nm CCD Filter - 2" - SII-2

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SKU: ASF-SII-2

Astronomik SII 12 nm CCD Filter - 2" Round Mounted


  • Mounted in a round, 2" threaded cell, the Astronomik SII CCD Filter is made for astrophotography
  • By designing the SII 12 nm CCD Filter with regards to peak technical standards, Astronomik has created a filter that provides the optical performance you seek for deep sky CCD imaging applications
  • Permits the light of ionized sulfur (SII) to be transmitted while obstructing close to the rest of the visual spectrum plus IR
  • FWHM bandwidth of nearly 12 nm
  • Perfect for imaging planetary nebulae as well as vestiges of supernovae as it blocks all undesired light pollution
  • Made in Germany, a country recognized for producing high quality optics!


More About the Astronomik 2" SII 12 nm CCD Filter


For performing CCD photography tasks, this 2" Round Mounted SII CCD narrowband filter from Astronomik is ideal. With an FWHM (full width at half maximum) of 12 nm, the Astronomik SII CCD is optimal for common CCD cameras, allowing the use of exceptionally fast optics. The focal ratio application range stretches from 1:2.8 to 1:15. Transmission losses and chromatic aberrations only transpire with Astronomik filters when excessively bright 1:2 or more aperture ratios are used, unlike other filters. It should be acknowledged that this filter features a transmission of up to 99%. Another benefit of 12 nm filters is the high availability of guiding stars for cameras that incorporate an autoguider.

The Astronomik SII 12 nm CCD Filter improves the contrast between objects, in this instance between objects that emit in the ionized sulfur (SII) lines and the skyglow background. Artificial light from mercury and sodium vapor as well as skyglow is completely blocked, making this an excellent filter for dealing with heavy light pollution. With the Astronomik SII 12 nm CCD Filter, you'll observe razor sharp stars identical to those you see using your regular telescope because of the supreme optical quality of the substrate.

All undesired wavelengths in the visible and IR spectral bands are completely obstructed with the Astronomik 2" SII 12 nm CCD Filter. Parfocal with all other filters from Astronomik, the SII-2 has an ultra thin substrate, and is diffraction limited to maintain the optical efficiency of your telescope. Coatings provide total resistance to blemishes caused by scratching, aging, and high humidity. This Astronomik filter arrives in a durable plastic filter case of superior quality.

Transmission Specifications


  • More than 97% transmission in the SII line
  • The rest of the visual spectrum is almost entirely blocked
  • Rejects wavelengths in the infrared