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Astronomik SII 12 nm CCD Filter - 27 mm Round - SII-27

SKU: ASF-SII-27

Astronomik SII 12 nm CCD Filter - 27 mm Round

  • Astronomik SII CCD Filters are made for CCD photography with this particular model configured in a 27 mm round format
  • Made to the highest technical standards to provide the optical efficiency necessary to execute deep sky imaging applications with your CCD camera
  • Permits the light of ionized sulfur (SII) to be transmitted while obstructing close to the rest of the visual spectrum plus IR
  • Approximate FWHM bandwidth of 12 nm
  • Ideally suited for imaging planetary nebulae and supernova residue
  • German-designed for high optical quality!


More About Astronomik SII 12 nm CCD Filters

For performing CCD photography tasks, this 27 mm 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.

An excellent filter for dealing with heavy light pollution, the Astronomik SII 12 nm CCD Filter boosts contrast between objects in the SII emission line and the skyglow background while completely suppressing the emission lines of artificial mercury (Hg) and sodium (Na) light, as well as skyglow. With the Astronomik SII 12 nm CCD Filter, you'll observe razor sharp stars identical to those you're used to seeing with your regular telescope due to the supreme quality of the substrate.

This Astronomik SII CCD filter provides complete blockage of all superfluous wavelengths in the visible and IR spectral bands. It has a very thin substrate, and is parfocal with all other Astronomik filters. Diffraction limited, this filter will not reduce the optical performance of your telescope. Coatings offer complete protection from scratching as well as the impacts of aging and high humidity. All Astronomik filters are delivered in a durable, high quality plastic filter box.

Transmission Specifications

  • 97%+ ionized sulfur (SII) line transmission
  • Obstructs almost the complete rest of the visual spectrum
  • Obstructs undesirable wavelengths in the Infrared