Baader Planetarium 1.25" Dark Blue Eyepiece Filter - 435 nm Bandpass - FCFDB-1

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  • This Baader 1.25" Dark Blue Filter provides maximum brightness without reflections, ghosting, or stray light
  • Fine optical plane parallel polishing inside 30 arcseconds
  • This high quality 435 nm bandpass filter is similar in color to the Wratten #38A filter
  • Features professional 7-layer multi-coatings for a resulting image that doesn't have false reflections
  • Stackable 1.25" filter cell with both male and female threads to enable any combination of filters you desire
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  • Description

    Baader Planetarium 435 nm Bandpass Dark Blue Eyepiece Filter - 1.25"

    Freedom from Ghost images, even when stacked. To avoid wedge errors, striae-free substrates are polished parallel to 30 seconds. First-class 7-layer hard multi-coatings on each face have 0.25% residual reflections. Baader filters are unique in this way as no other colored filter includes anti-reflection multicoatings. In addition, these coatings differ depending on the filter so that the coating performance matches the filter curve of each color. This increases transmission while decreasing reflections.

    Extremely High Transmissions result in maximum contrast and isolation of planetary details, even with smaller telescopes. Efficiencies of the three longpass filters (Red, Orange, and Yellow) peaks at 98%, and efficiencies of the three bandpass filters (Green, Blue, Dark Blue) achieve 70%. 

    Carefully designed spectral characteristics. Filters may be stacked without image degradation or ghosting, in order to provide even narrower passbands. Or, combine with any of the other Baader filters for interesting possibilities.

    No reduction in sharpness, even at high magnifications or when using the filter far ahead of the focal plane (ie, digital imaging, or in front of a diagonal or binoviewer). 



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    Shipping Restrictions

    Only ships in contiguous USA.

    What's Included

    • Baader Planetarium 1.25" 435 nm Bandpass Dark Blue Eyepiece Filter

  • Dimensions & Specifications

    • Filter Size: 1.25"
    • Filter Type: Planetary Color
    • Filter Shape: Round
    • Mounted/Unmounted: Mounted
    • Wratten Number or Equivalent: #38A Blue

  • Product Guarantee

    We stand behind all the products we sell, and your satisfaction is our top priority. If you're not satisfied with the quality of your purchase, simply send the item back to us in its original packaging within 30 days of its delivery.

    Manufacturer Warranty

    This product has a 2 year manufacturer's warranty against defects is provided. If you have specific questions about this product's warranty please contact Alpine Astronomical's Customer Service department by email at service@alpineastro.com.

    Return & Exchange Policy

    At our site, returns are easy! You may return new, unused, and resalable items for a refund or exchange. Simply ensure that the item is returned in its original product packaging within 30 days of delivery.

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