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Antlia H-beta and OIII Visual Filter - 1.25"

Antlia H-beta and OIII Visual Filter - 1.25"

by Antlia
SKU ANT-HB-OIII-1.25
CA$141.00 - CA$141.00
CA$141.00
CA$141.00 - CA$141.00
CA$141.00
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  • Passes the H-beta (486.1nm) and both OIII (495.9nm, 500.7nm) emission lines
  • Peak transmission greater than 90% at 486.1nm, 495.9nm, and 500.7nm
  • OD4 blocking of unwanted wavelengths @ 300-1000nm
  • Lambda/4 or better transmitted wavefront
  • Standard 1.25" filter cell (M28.5x0.6)
3 in stock
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  • Description
  • FAQ
  • Specifications
  • In the Box
  • Warranty

  • Antlia H-beta and OIII Visual Filter - 1.25"

    The Antlia H-beta and OIII filter is engineered for high-contrast visual nebula observation and deep-sky astrophotography, with peak transmission above 90% at the critical wavelengths: H-Beta (486.1nm) and both Oxygen III lines (495.9nm and 500.7nm). OD4 blocking from 300-1000nm darkens the sky background, so faint objects become much more visible against it under both light-polluted and dark skies. The 1.25" filter is built on a 2mm optical substrate with a Lambda/4 or better transmitted wavefront.

    H-beta and OIII in One Filter: >90% Peak Transmission

    This filter passes the light of hydrogen (H-beta) and doubly ionized oxygen (OIII) emission. With peak transmission above 90% at the 486.1nm H-beta line and the 495.9nm/500.7nm OIII lines, you will notice a much higher contrast boost on planetary nebulae, supernova remnants, emission nebulae, diffuse nebulae and extremely faint nebulae.

    This model is a dual-band filter: one filter covers both the H-beta and OIII lines. It produces near-photographic views of the Veil, Dumbbell and Orion nebulae, among many other objects.

    Darker Sky Background: OD4 Blocking from 300-1000nm

    The filter is coated with OD4 suppression of unwanted wavelengths over a 300-1000nm cut-off range, which meets the spectral requirements of photographic cameras and further enhances suppression of the IR region. Compared with visual filters with a cut-off depth of OD3 @ 350-750nm, it performs better to darken the sky background and makes deep-sky observation and photography of nebulae, star clusters and galaxies easier.

    Imaging-Grade Optics for Visual Use: Lambda/4 Wavefront

    Antlia builds this filter on a single, non-glued optical substrate. The transmitted wavefront is Lambda/4 or better, and parallelism is less than 30 arcseconds.

    • Substrate Thickness: 2mm +/-0.05mm.
    • Surface Quality: S/D (scratch/dig) 60/40, referring to MIL-O-13830.
    • Ultra-Thin Cell: The black anodized, laser engraved 1.25" filter ring (M28.5x0.6) is ultra-thin to minimize vignetting by maximizing the clear aperture.

    Since human eyes are less sensitive at night, large aperture telescopes are recommended to gather light and funnel it into the observer's eye.

  • How does the Antlia HB-OIII filter improve views of the Veil Nebula (NGC 6960)?

    The Veil Nebula is a supernova remnant that emits in OIII and H-beta light. The Antlia HB-OIII filter passes these lines with >90% peak transmission while its OD4 blocking darkens the sky background. It produces near-photographic views of the Veil, under both light-polluted and dark skies.

    What is the advantage of the Antlia HB-OIII's OD4 blocking?

    OD4 blocking means the filter passes only 0.01% of unwanted light across its 300-1000nm cut-off range. Compared with visual filters rated OD3 @ 350-750nm, that is ten times deeper blocking over a wider range, including the IR region. This performs better to darken the sky background for observation and photography.

    Which objects does Antlia recommend the HB-OIII filter for?

    Targets include planetary nebulae, supernova remnants, emission nebulae, diffuse nebulae and extremely faint nebulae, and the filter produces near-photographic views of the Veil, Dumbbell and Orion nebulae, among many other objects. For visual use, a large aperture telescope is recommended.

    Can I use the Antlia 1.25" HB-OIII filter for astrophotography?

    Yes. Antlia engineered it for both visual observation and deep-sky astrophotography. With astronomical cameras and DSLRs, it enhances the details of the OIII and H-Beta emission lines, and its OD4 cut-off range of 300-1000nm meets the spectral requirements of photographic cameras.

    Why is a large aperture telescope recommended for using the Antlia HB-OIII filter visually?

    Since human eyes are less sensitive at night, large aperture telescopes are recommended to gather light and funnel it into the observer's eye. A larger aperture gives a brighter image of the nebula at the eyepiece.

    Will this Antlia filter work in my 1.25" filter wheel?

    The filter uses Antlia's standard 1.25" (M28.5x0.6) threaded cell, so it fits filter wheels and eyepieces that take standard threaded 1.25" filters. Antlia made the ring ultra-thin to minimize vignetting by maximizing the clear aperture.

  • Filter Type H-beta and OIII filter for visual and photography (Antlia model: Broadband)
    H-Beta Passband CWL 486.1nm, >90% Peak Transmission
    Oxygen III Passband 1 CWL 495.9nm, >90% Peak Transmission
    Oxygen III Passband 2 CWL 500.7nm, >90% Peak Transmission
    Blocking Range OD4 @ 300-1000nm
    Filter Thickness 2mm +/-0.05mm
    Substrate Optical, single / non-glued
    Transmitted Wavefront Lambda/4 or better
    Parallelism < 30 arcseconds
    Surface Quality 60/40 Scratch/Dig (MIL-O-13830)
    Filter Cell 1.25" Mounted (M28.5x0.6)
    Cell Construction Ultra-thin, black anodized, laser engraved
    Recommended Use Visual observation (large aperture telescopes recommended) and deep-sky astrophotography
    Not Recommended For Solar imaging and observing
    Safety Warning Do not look at the Sun with this filter
    Filter Size 1.25" mounted

    • Antlia H-beta and OIII Visual Filter - 1.25"

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  • Contact us for warranty details.