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Antlia 3nm Narrowband H-Beta Pro Filter - 2"
Antlia 3nm Narrowband H-Beta Pro Filter - 2"
Antlia 3nm Narrowband H-Beta Pro Filter - 2"
Antlia 3nm Narrowband H-Beta Pro Filter - 2"

Antlia 3nm Narrowband H-Beta Pro Filter - 2"

by Antlia
SKU ANT-HB-3NM-2
$395.00 - $395.00
$395.00
$395.00 - $395.00
$395.00
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  • Isolates the H-Beta emission line at 486.1nm
  • Ultra-narrow 3nm bandpass for maximum contrast
  • High 88% peak transmission for strong signal
  • Usable down to f/3 with minimal loss of signal
  • 2" mounted format with M48x0.75 threads
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  • Description
  • FAQ
  • Specifications
  • In the Box
  • Warranty

  • Antlia 3nm Narrowband H-Beta Pro Filter - 2"

    The Antlia 3nm Narrowband H-Beta Pro filter isolates the hydrogen-beta emission line at a central wavelength of 486.1nm with an extremely tight 3nm full width at half maximum (FWHM). This narrow bandpass achieves a peak transmission of 88% while delivering greater than OD5 out-of-band blocking from 300-1100nm. Built on a single, non-glued optical substrate with a transmitted wavefront of Lambda/4 or better, the filter can be used down to f/3 with minimal loss of signal, in light-polluted areas and at dark sites.

    3nm Bandpass at 486.1nm: Isolate H-Beta with 88% Transmission

    By restricting the incoming light to a 3nm window centered on 486.1nm, the Antlia H-Beta Pro enhances the contrast of emission targets by reducing unwanted background signals. With 88% transmission at the 486.1nm line, it provides strong signal and well-defined nebula structures on H-Beta emission nebulae such as the California Nebula (NGC 1499). Antlia notes the filter is only effective for deep-sky objects that contain H-Beta emissions.

    OD5 Blocking and Lambda/4 Optics: Suppressing Halos and Noise

    The filter's construction is critical for clean data. Its greater than OD5 blocking, which attenuates unwanted wavelengths by a factor of 100,000, ensures an excellent signal-to-noise ratio and minimizes interference from other wavelengths. A single substrate eliminates internal reflections, the transmitted wavefront is Lambda/4 or better with parallelism of less than 30 arcseconds, and the steep spectral profile minimizes halos around bright stars.

    Usable Down to f/3: Built for Fast Optics

    A key challenge with narrowband filters is band-shifting in fast optical systems. The Antlia 3nm Pro series is specifically designed to be used down to f/3 with minimal signal loss. This makes it a practical choice for fast imaging systems down to that focal ratio.

    Antlia 3nm Pro vs. Wider H-Beta Filters: A Contrast Trade-Off

    Compared to filters with a 7nm or wider bandpass, the Antlia 3nm Pro offers a significant advantage in contrast, particularly from urban or suburban locations. The trade-off for this enhanced contrast is a need for longer exposure times to achieve the same signal level.

    • Antlia 3nm Pro: Delivers higher contrast by rejecting more background light. Antlia notes it can be used in light-polluted areas and dark sites, and extends imaging time when the moon is up.
    • Wider 7nm+ Filters: Capture more signal in a shorter time frame and are more forgiving of slight band-shifting on very fast systems (below f/4). However, they allow more background signal through, reducing overall contrast.

  • Why would I choose the Antlia 3nm H-Beta Pro filter over an H-Alpha or OIII filter?

    The Antlia 3nm H-Beta Pro is a specialized filter for objects that have strong hydrogen-beta emissions but may be weaker in other wavelengths. Antlia notes it is only effective for deep-sky objects that contain H-Beta emissions, such as the California Nebula (NGC 1499). As part of the 3nm Pro series alongside Ha, SII, OIII and NII, it adds another channel for combining narrowband data in post-processing.

    Can I use the Antlia 3nm H-Beta Pro filter for visual observation?

    No. Antlia lists night visual observation as not recommended for this filter. It is designed for astrophotography of deep-sky objects that contain H-Beta emissions.

    How does the >OD5 blocking on the Antlia H-Beta Pro improve my images?

    OD5 blocking means out-of-band light, such as light pollution outside the passband, is reduced to 0.001% (a factor of 100,000) across 300-1100nm. Antlia rates this as ensuring an excellent signal-to-noise ratio and minimizing interference from other wavelengths.

    Will the Antlia 3nm H-Beta Pro work well with my f/3.5 Newtonian astrograph?

    Yes. Antlia states that all its narrowband Pro filters can be used down to f/3 with minimal loss of signal, so an f/3.5 system is within that range.

    What is the benefit of the single substrate design of the Antlia H-Beta Pro?

    The single, non-glued substrate with a transmitted wavefront of Lambda/4 or better is used to eliminate internal reflections. Together with a steep spectral profile that minimizes halos around bright stars, Antlia says this optical reliability reduces post-image processing.

    Is the Antlia 3nm H-Beta Pro filter safe for solar imaging?

    No. Antlia lists solar imaging as not recommended and warns: DO NOT LOOK AT THE SUN WITH THIS FILTER DIRECTLY. Serious eye damage will result if you fail to observe the warning. It is designed for imaging deep-sky objects that contain H-Beta emissions.

  • Filter Type H-Beta Narrowband (3nm Pro series)
    Central Wavelength (CWL) 486.1nm
    Bandpass (FWHM) 3nm
    Peak Transmission 88%
    Blocking Range 300-1100nm
    Blocking Depth >OD5 (0.001%)
    Recommended F-Ratio Usable down to f/3 with minimal loss of signal
    Filter Size 2" Mounted (M48x0.75 Threads)
    Filter Thickness 2mm +/-0.05mm
    Substrate Optical, single / non-glued
    Surface Quality 60/40 (per MIL-O-13830)
    Transmitted Wavefront Lambda/4 or better
    Parallelism < 30 arcseconds
    Usage Warning Not recommended for solar imaging or night visual observation. Do not look at the Sun with this filter directly.

    • Antlia 3nm Narrowband H-Beta Pro Filter - 2"

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    • Protective Case

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  • 3-Year Manufacturer Warranty against Delamination.