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Astronomik UHC-E Filter - 31 mm Round - UHCE-31

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SKU: ASF-UHCE-31 Available Used from $60.00

Astronomik 31 mm UHC-E Filter

Astronomik UHC-E filters are ideal for those on a budget who still want to observe comets and deep sky emission nebulae in areas with heavy light pollution. Optimally equipped for smaller instruments with apertures up to 5" (125 mm), this filter obstructs unwanted light from sources such as streep lamps and background skyglow, while increasing the contrast of emission nebulae and comets.

Providing an FWHM (full width at half maximum) of 45 nm, this Astronomik UHC-E filter emphasizes the contrast between the object you want to see and the background sky, but in a reduced manner when compared to the UHC filter. However, a larger amount of starlight is transmitted. Therefore, the UHC-E filter works better for telescopes with smaller apertures.

Astronomik UHC-E Filter Highlights

  • This 31 mm Round UHC-E Filter from Astronomik is an ideal fit for use with smaller telescopes with up to 5" (125 mm) apertures
  • For imaging in severe light pollution, this filter emphasizes the contrast between deep sky emission nebulae and the skyglow background
  • Due to the UHC-E filter's high FWHM of 45 nm, comet observation is attainable when it passes through a spectral line of Carbon
  • 94% maximum transmission
  • Transmission range of 480 nm to 525 nm as well as 645 nm and above
  • 1 mm glass thickness
  • Parfocal with all other filters produced by Astronomik
  • Multi-layer coatings offer complete resistance to the impacts of scratching, aging, and high humidity
  • This filter is diffraction limited and therefore will not compromise your telescope's optical performance
  • Each Astronomik filter comes with a durable plastic storage case of superior quality

Transmission Specifications

  • 94% transmission at 486 nm (H-beta)
  • 95% transmission at 496 nm (OIII)
  • 95% transmission at 501 nm (OIII)
  • 90% transmission at 656 nm (H-alpha)
  • Transmits from 465 nm to 530 nm as well as over 645 nm
  • Blocks all undesirable wavelengths