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Baader Ultra-Narrowband H-alpha 3,5nm Filter

$297.00
SKU FHALNU-1 (Baader #2459451)
Filter size

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Description
  • Precision grade enforced H-alpha filter for f/10 to f/3.5 optical systems
  • Opens up the extremely narrow 3,5nm H-alpha world
  • This enforced contrast results in even fainter stars, providing more signal of faintest nebulae detail
  • Manufacturing such ultra-narrow filter does require extreme coating homogeneity and very high CWL precision, which these filters are designed for. CWL= Center-wavelength / FWHM= full width half maximum.

      Baader's New Ultra Narrowband Enforced Filters

      These three sizes of Ultra-Narrowband filters open up the extremely narrow H-alpha, O-III, and S-II world. This enforced contrast provides more signal of the faintest nebula detail. Manufacturing such ultra-narrow filters requires extreme coating homogeneity and very high Center Wavelenth Precision, which these filters have been designed for. Designed for use on optical systems from f/10 to f/3.5.

      Now available in all popular sizes; 1.25"Mounted, 2" Mounted, 31mm Round, 36mm Round, 50.4mm Round, 50x50 Square, and 65x65mm Square.

      NOTE: In general, the H-alpha ultra narrowband filter is not suitable for solar observation. The half-bandwidth of 3.5nm equals 35 angstroms, much wider than needed for high quality solar observation (sub-angstrom). Never use this filter for visual observation of the sun.

      Why Baader Planetarium Filters?

      Specifications

      1.25"

      MANUFACTURER Baader Planetarium
      SKU (#) 2459451
      WEIGHT (KG) 0.066
      COLOUR Black
      TRANSMISSION RANGE H-alpha
      FILTER THICKNESS (WITHOUT CELL) 2 mm
      HBW (HALFBANDWIDTH) 3,5 nm
      CWL (CENTRAL WAVELENGTH) 656,3 nm
      AR-COATING dielectrically coated, planeoptically polished
      SPECIAL FEATURES enforced Narrowband
      FILTER SIZE 1 25 inch
      FILTER USAGE CCD, Deep Sky, H-alpha
      FILTER MOUNTED Mounted (LPFC 6mm)
      TYPE OF FILTER Narrowband
      SINGLE OR SET? Single Filter
      FILTER SHAPE round

      2"

      MANUFACTURER Baader Planetarium
      SKU (#) 2459454
      EAN CODE 4047825032171
      WEIGHT (KG) 0.066
      TRANSMISSION RANGE H-alpha
      FILTER THICKNESS (WITHOUT CELL) 2 mm
      HBW (HALFBANDWIDTH) 3,5 nm
      CWL (CENTRAL WAVELENGTH) 656,3 nm
      AR-COATING dielectrically coated, planeoptically polished
      FILTER SIZE 2 inch
      FILTER USAGE CCD, Deep Sky, H-alpha
      FILTER MOUNTED Mounted (LPFC 6mm)
      TYPE OF FILTER Narrowband
      SINGLE OR SET? Single Filter
      FILTER SHAPE round

      31mm

      MANUFACTURER Baader Planetarium
      SKU (#) 2459452
      WEIGHT (KG) 0.066
      COLOUR Black
      TRANSMISSION RANGE H-alpha
      FILTER THICKNESS (WITHOUT CELL) 2 mm
      HBW (HALFBANDWIDTH) 3,5 nm
      CWL (CENTRAL WAVELENGTH) 656,3 nm
      AR-COATING dielectrically coated, planeoptically polished
      SPECIAL FEATURES enforced Narrowband
      FILTER SIZE 31 mm
      FILTER USAGE CCD, Deep Sky, H-alpha
      FILTER MOUNTED Unmounted
      TYPE OF FILTER Narrowband
      SINGLE OR SET? Single Filter
      FILTER SHAPE round

      36mm

      MANUFACTURER Baader Planetarium
      SKU (#) 2459453
      WEIGHT (KG) 0.066
      COLOUR Black
      TRANSMISSION RANGE H-alpha
      FILTER THICKNESS (WITHOUT CELL) 2 mm
      HBW (HALFBANDWIDTH) 3,5 nm
      CWL (CENTRAL WAVELENGTH) 656,3 nm
      AR-COATING dielectrically coated, planeoptically polished
      SPECIAL FEATURES enforced Narrowband
      FILTER SIZE 36 mm
      FILTER USAGE CCD, Deep Sky, H-alpha
      FILTER MOUNTED Unmounted
      TYPE OF FILTER Narrowband
      SINGLE OR SET? Single Filter
      FILTER SHAPE round

      50.4mm

      MANUFACTURER Baader Planetarium
      SKU (#) 2459455
      EAN CODE 4047825032188
      WEIGHT (KG) 0.066
      TRANSMISSION RANGE H-alpha
      FILTER THICKNESS (WITHOUT CELL) 3 mm
      HBW (HALFBANDWIDTH) 3,5 nm
      CWL (CENTRAL WAVELENGTH) 656,3 nm
      AR-COATING dielectrically coated, planeoptically polished
      FILTER SIZE 50.4 mm
      FILTER USAGE CCD, Deep Sky, H-alpha
      FILTER MOUNTED Mounted (LPFC 6mm)
      TYPE OF FILTER Narrowband
      SINGLE OR SET? Single Filter
      FILTER SHAPE round

      50x50mm

      MANUFACTURER Baader Planetarium
      SKU (#) 2459456
      EAN CODE 4047825032195
      WEIGHT (KG) 0.066
      TRANSMISSION RANGE H-alpha
      FILTER THICKNESS (WITHOUT CELL) 3 mm
      HBW (HALFBANDWIDTH) 3,5 nm
      CWL (CENTRAL WAVELENGTH) 656,3 nm
      AR-COATING dielectrically coated, planeoptically polished
      FILTER SIZE 50 x 50 mm
      FILTER USAGE CCD, Deep Sky, H-alpha
      FILTER MOUNTED Mounted (LPFC 6mm)
      TYPE OF FILTER Narrowband
      SINGLE OR SET? Single Filter
      FILTER SHAPE round

      65x65mm

      MANUFACTURER Baader Planetarium
      SKU (#) 2459457
      WEIGHT (KG) 0.073
      COLOUR Black
      TRANSMISSION RANGE H-alpha
      FILTER THICKNESS (WITHOUT CELL) 3 mm
      HBW (HALFBANDWIDTH) 3,5 nm
      CWL (CENTRAL WAVELENGTH) 656,3 nm
      AR-COATING dielectrically coated, planeoptically polished
      SPECIAL FEATURES enforced Narrowband
      FILTER SIZE 65 x 65 mm
      FILTER USAGE CCD, Deep Sky, H-alpha
      FILTER MOUNTED Unmounted
      TYPE OF FILTER Narrowband
      SINGLE OR SET? Single Filter
      FILTER SHAPE square
      Downloads

      FAQ - Problems with filters can have the strangest causes

      Halos - No Problem!