ZWO 31mm Narrowband Filter Set with OIII, SII, & Ha Filters - NB7nmD31

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  • These 31mm unmounted narrowband filters feature fine-optical polishing for 1/4 wave precision, as well as multiple layers of anti-reflection coatings
  • Each filter comes with a protective plastic filter container
  • Three unmounted 31mm narrowband imaging filters, H-Alpha, SII, and OIII, are included in this set
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  • Description

    ZWO Narrowband Filter Set with 31mm OIII, SII, and H-Alpha Filters

    All of the 31mm filters in this ZWO Narrowband Filter Set are unmounted. These narrowband filters are fine-optically polished to reach an accuracy of 1/4 wave. Their performance is further enhanced by multiple layers of anti-reflection coatings.

    ZWO 31mm Unmounted OIII Filter

    OIII, or doubly ionized oxygen, emits light in the blue/green, or teal portion of the spectrum near 500 nm. Planetary nebulae and supernova remnants emit most of their light in the OIII line.

    ZWO 31mm Unmounted Ha Filter

    Hydrogen-Alpha is the most dominant emission line in star-forming regions. H-Alpha light is created by atomic hydrogen, and is responsible for the red color seen in most nebulae.

    ZWO 31mm Unmounted SII Filter

    Sulfur is in the deep red of the spectrum near 672 nm. When combined with H-a and OIII, these three filters will produce images with colors that are reminiscent of those taken by the Hubble Space Telescope.







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    What's Included

    • ZWO 31mm Round Unmounted H-Alpha Filter
    • ZWO 31mm Round Unmounted SII Filter
    • ZWO 31mm Round Unmounted OIII Filter
    • 3x Plastic Filter Cases

  • Dimensions & Specifications

    • Filter Size: 31mm
    • Filter Type: Narrowband Imaging
    • Filter Shape: Round
    • Mounted/Unmounted: Unmounted
    • Filter Set Contents: Ha; OIII; SII

  • 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

    2 years

    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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