Skip to content
IMPORTANT: Our store is located in Canada. All orders that include products manufactured outside of Canada or USA will be subject to tariffs and duties, regardless of the order value. US customers are responsible for all applicable duties and tariffs, and those will be billed by the carrier, except for the Lacerta upgrade kit, for which we collect them at checkout.
IMPORTANT: Our store is located in Canada. All orders that include products manufactured outside of Canada or USA will be subject to tariffs and duties, regardless of the order value. US customers are responsible for all applicable duties and tariffs, and those will be billed by the carrier, except for the Lacerta upgrade kit, for which we collect them at checkout.
Baader Planetarium Baader H-alpha 1.25" Bandpass Filter (20nm)
Baader Planetarium H-alpha Bandpass Filter (20nm)
Baader Planetarium H-alpha Bandpass Filter (20nm)
Baader Planetarium Baader H-alpha 2" Bandpass Filter (20nm)
Baader Planetarium H-alpha Bandpass Filter (20nm)
Baader Planetarium H-alpha Bandpass Filter (20nm)
Baader Planetarium Baader H-alpha 1.25" Bandpass Filter (20nm)
Baader Planetarium Baader H-alpha 2" Bandpass Filter (20nm)

Baader Planetarium H-alpha Bandpass Filter (20nm)

by Baader Planetarium
SKU BAA-2961850
$115.00 - $201.00
$115.00
$115.00 - $201.00
$115.00
Price Match Policy!
  • H-alpha Bandpass Filter in 1.25" & 2" Sizes
  • 20nm FWHM Bandwidth
  • 656.3nm Center Wavelength
  • Optimized for Color CMOS/CCD Cameras
  • High-Contrast for Visual and Photographic Use
Backordered
Request Stock Alert
Availability Info
Qualifies for FREE Shipping in CONUS on orders over $350.
  • Description
  • FAQ
  • Specifications
  • In the Box
  • Downloads
  • Warranty

  • Baader H-alpha Bandpass Filter (20nm)

    The Baader H-alpha Bandpass filter, available in 1.25" and 2" sizes, isolates the critical 656.3nm wavelength of ionized hydrogen with a 20nm FWHM, dramatically increasing the contrast of emission nebulae. This filter is engineered for both visual deep-sky observing and as a powerful enhancement for color CMOS and CCD cameras, allowing you to cut through light pollution and capture detailed H-II regions from any location.

    A 20nm Bandpass for High-Contrast Deep-Sky Views

    By selectively passing a 20nm window of light centered on the 656.3nm H-alpha line, this filter renders the sky background profoundly dark. This isolates the faint, glowing structures of emission nebulae like the North America Nebula (NGC 7000), making them stand out against a black field of view. The 20nm bandwidth is a carefully chosen compromise, offering a significant contrast boost while remaining bright enough for effective visual use in a variety of telescopes.

    Optimized for Color CMOS and CCD Imaging at 656.3nm

    For imagers using one-shot color cameras, this filter acts as a supercharged red filter. It replaces the standard red channel in an RGB sequence, dedicating all your signal collection at that wavelength to the most important structures in emission nebulae. This technique allows you to produce high-contrast, detailed images of H-II regions without investing in a full monochrome camera and narrowband filter set.

    Visual Enhancement for All Telescope f-ratios

    Unlike extremely narrow imaging filters that can be too dim for the human eye, the 20nm bandpass provides a tangible boost in nebular visibility without an excessive loss of light. This filter is designed to work effectively across all telescope f-ratios, making it a versatile tool for any observer looking to punch through local light pollution and reveal the hidden structure in faint deep-sky objects.

    • Important Safety Warning: This filter is designed for nighttime deep-sky observing only. It is NOT a solar filter and must never be used for direct viewing of the sun. Permanent eye damage will result.

  • What is the Baader 20nm H-alpha filter primarily used for?

    This filter is designed to dramatically increase the contrast of emission nebulae (H-II regions) for both visual observing and astrophotography. It isolates the 656.3nm H-alpha wavelength, making objects like the North America Nebula (NGC 7000) or the Orion Nebula (M42) stand out, especially from light-polluted areas.

    Why choose a 20nm bandpass for the Baader H-alpha filter instead of a narrower one like 7nm?

    A 20nm bandpass offers a crucial balance. It's narrow enough to provide a major contrast enhancement by blocking light pollution, but wide enough to remain bright for visual observing. Narrower filters (like 7nm or 3nm) are excellent for imaging but are often too dim for the human eye to see through, especially with smaller telescopes.

    How will the Baader 20nm H-alpha filter improve my images of the North America Nebula (NGC 7000) with a color camera?

    When used with a color CMOS or CCD camera, this filter acts as an enhanced red filter. It isolates the rich H-alpha signal from the nebula while rejecting skyglow, moonlight, and other sources of light pollution. This results in a much stronger, more detailed signal from the nebula's structure, allowing you to capture impressive images even from a suburban backyard.

    Can I use the Baader 20nm H-alpha filter with my f/5 Newtonian for visual observing?

    Yes, absolutely. The filter is designed to perform well across all f-ratios, including faster systems like an f/5 Newtonian. The 20nm bandwidth ensures the view remains bright enough to be effective, providing a significant contrast boost on emission nebulae without dimming the image excessively.

    Is the Baader 20nm H-alpha filter safe for viewing the sun?

    NO. This is not a solar filter. You must never use this filter for any type of solar observation. Viewing the sun through this filter without a proper, full-aperture solar filter will cause immediate and permanent eye damage.

    Which size of the Baader 20nm H-alpha filter fits my filter wheel and eyepieces?

    Choose the size that matches your accessories. The 1.25" version is housed in a standard 1.25" cell with standard filter threads and threads directly into the barrel of any 1.25" eyepiece or into a standard 1.25" filter wheel. The 2" version is the right choice if your eyepieces, diagonal or filter wheel use the 2" format. Both sizes offer the same 20nm bandpass centered on 656.3nm.

  • 1.25" Round Mounted

    Filter Type H-alpha Bandpass
    Size 1.25"
    Bandwidth (FWHM) 20 nm
    Center Wavelength (CWL) 656.3 nm
    Primary Application Visual & Photographic Deep-Sky
    Solar Safe No

    2" Round Mounted

    Filter Type Bandpass
    Wavelength H-alpha
    Center Wavelength (CWL) 656.3 nm
    Bandpass (FWHM) 20 nm
    Filter Size 2"
    Primary Use Deep-Sky Visual & Photography
    Solar Safe No
  • Baader Planetarium Warranty