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Astronomik CLS CCD Light Pollution Filter - SC Rear Cell - CLSCCD-SCT

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SKU: ASF-CLSCCD-SCT

Astronomik CLS-CCD Light Pollution Filter - SCT Rear Cell


  • Simultaneously allows the largest portion visible light and h-alpha emissions to pass while blocking mercury and sodium-vapor spectral lines from street lamps, thus eliminating that irritating orange glare caused by light pollution in urban areas
  • The Astronomik CLS-CCD Filter exhibits more stars and detail in nebulae
  • Suited for DSLR, CCD, and black & white film photography, as well as for viewing deep sky objects with f/3 and above telescopes and photo lenses of all apertures
  • Mounted in a round, SCT rear cell format
  • Allows nearly 100% transmission in the visual and H-alpha portion of the spectrum, 450 nm to 530 nm
  • Multi-layer coatings are standard on all Astronomik filters to reduce the effects of scratching, aging, and high humidity
  • Made in Germany, a country known for high quality optics!


More About the Astronomik SCT Rear Cell CLS-CCD Filter


The Astronomik CLS CCD Filter is compatible for use with DSLR Cameras, now remodeled for astronomical use, under extremely light-polluted surroundings. This filter greatly emphasizes the contrast between astronomical objects and the background. The CLS-CCD Filter distinguishes itself from the UHC Filter by its wider transmission curve, causing more light to be transmitted for sharper stars. It has been enhanced to block as much spurious light as possible while enabling the best performance for desirable wavelengths.

An excellent filter for deep sky observing, as well as for DSLR, CCD, and black & white film applications. The CLS-CCD Filter eliminates most surrounding light pollution, doing away with that irritating orange glare. Best equipped for use with f/3 and above focal ratio telescopes or photo lenses of any aperture, this filter will completely block emissions from artifical light sources while permitting light from desired wavelengths to pass.

Other applications for this filter include more convenient resolution of Double Stars as well as color imaging from emission line data in the Luminance channel. Like all Astronomik filters, the CLS-CCD is parfocal with any other filter from Astronomik. This 1 mm thick filter is diffraction limited and will not lower your telescope's optical performance. It is highly resistant to blemishes caused by scratching, aging, and high humidity. All Astronomik filters include a durable, high-quality plastic storage case.

Transmission Specifications:


  • 92% transmission at 486 nm (H-beta)
  • 92% transmission at 496 nm (OIII)
  • 92% transmission at 501 nm (OIII)
  • 97% transmission at 656 nm (H alpha)
  • Pass from 450 to 540 nm and from 640 nm to 690 nm
  • Blocks the Infrared wavelengths