Open Box Astrodon SLOAN Y2 Filter 50mm Round Unmounted

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Open Box Astrodon SLOAN Y2 Filter 50mm Round Unmounted

Astrodon SLOAN Y2 Filter 50mm Round Unmounted

The original Sloan Digital Sky Survey (SDSS) filters include five mostly non-overlapping filters covering 300 nm to the sensitivity limit of silicon CCD cameras near 1100 nm. They combined colored glass filters and short-pass dielectric coatings to steepen the low wavelength side of the bandpass. The (sky) emission line at 557.7 nm occurs between the g' and r' filters, and is reduced by using the SDSS filters.

The SDSS photometric system is the most common filter set used today. Typical research photometry up to magnitude 23 will be performed in this system, with professional (meter-class) telescopes. The Hubble Space Telescope is equipped with an SDSS set, and provides a large reference database for research.

With the Astrodon SLOAN Y2 Filter the following changes were made:


  • Better out-of-band blocking from Tave<=0.1% to Tabs<=0.03%.
  • Different 50%T points for the r' and i'
  • All filters come edge-blackened to reduce stray light reflections

  • These filters are parfocal with all Astrodon LRGB and narrowband filters.



  • 50% transmission points provided above (+/- 3nm typical)
  • Peak transmission guaranteed > 95% (>90% for u')
  • <=0.03%Tabs out-of-band 300 - 1100 nm
  • Striae-free, single fused silica substrates
  • 1/4-wave propagated wavefront prior to coating
  • 0.5 arcminute substrate parallelism
  • 3.000 +/-0.025 mm substrate thickness
  • 49.7 mm dia. unmounted

  • Manufacturer Product Number: SL-Y2-50R