The SVBONY H-beta SV132 1.25" 25 nm is a professional astronomical filter with a half-width transmission window (FWHM) of 25 nm. This filter was designed for visual observations of nebulae such as the California Nebula (NGC 1499) in the constellation of Perseus or the Horsehead Nebula (NGC 2023) in Orion.

This filter combines the ability to almost completely eliminate the unwanted component coming from sodium and mercury lamps with high transmittance for the Hβ spectral line (486.1 nm). Observation in the ionized hydrogen band together with very good separation of unwanted spectral lines significantly improves the contrast and increases the comfort of observing nebula objects. To ensure high durability and stability of optical parameters, the filter was made on a high-quality optical substrate covered with high-efficiency coatings and increased mechanical resistance.

Note! The Hβ filter is not recommended for visual observations or photography of the Sun.

Key Features of the SVBONY H-beta SV132 1.25" 25nm Filter

• a bandpass filter made on a high-quality glass substrate that transmits Hβ band lines
• dedicated to visual observations
• Full width half-width (FWHM) of 25 nm
• high ability to cut out light pollution

Technical parameters

• filter type: bandpass filter
• Filter diameter: 1.25"
• filter thickness: 1.85 mm
• filter shape: round
• transmitted bands: Hβ (486.1 nm)
• Half-width bandwidth (FWHM): 25 ± 3 nm
• maximum transmission for Hβ band: >80%
• blocked light pollution bands: mercury lamps 0.1% transmission for the 435 and 578 nm lines; sodium lamps 0.1% transmission for the 589 nm line
• blocking range: 400 - 700 nm
• filter coating: multi-layer coating (MC)
• surface finish quality: λ/4
• parallelism: <30"

Set components

• SVBONY H-beta SV132 filter 1.25" 25 nm

Guarantee

12 months