Svbony SV240 Multi-Narrowband Galaxy & Nebula NIR 1.25" is a professional astronomical filter designed for astrophotography conducted in conditions of strong light pollution - even to level 8 on the Bortle scale. Thanks to the effective blocking of emission characteristic of sodium and mercury lamps and high transmission in the key Hα, O-III and Hβ bands, it allows obtaining detailed images of nebulae and galaxies from urban areas.

The filter is made of high-quality optical glass, which ensures durability, resistance to deformation and stable transmission parameters. The 1.25" version is dedicated to astro cameras and accessories equipped with a standard M28.5 × 0.6 thread.

Note! The Svbony SV240 Multi-Narrowband Galaxy & Nebula NIR 1.25" filter is not intended for solar observations.

Key Features of the Svbony SV240 Multi-Narrowband Galaxy & Nebula NIR 1.25" Filter

• multi-band filter made on a high-quality glass substrate
• half-width of the transmission bands of the main emission lines (FWHM) of 24, 20 and 115 nm
• high capacity to cut urban light pollution

Technical parameters

• filter type: multiband filter
• Filter diameter: 1.25"
• filter shape: round
• transmitted bands: Hα, O-III, Hβ
• Half-width bandwidth (FWHM) for the Hα line: 24 nm
• transmission for Hα line band: >90%
• Full width half-bandwidth (FWHM) for the O III line: 20 nm
• transmission for the O III line band: >90%
• Half-width bandwidth (FWHM) for the Hβ line: 115 nm
• transmission for Hβ line band: >90%
• blocked light pollution bands: mercury lamps (435.8 nm, 546.1 nm, 577 nm, 578.1 nm), sodium lamps (598 nm, 589.6 nm, 615.4 nm, 616.1 nm)
• equivalent optical density for blocked lines: OD5 (300–450 nm); OD4 (560–620 nm); OD2 (690–750 nm); OD3 (940–1100 nm)
• surface finish quality: λ/4
• surface quality index: 60/40
• thread: M28.5 × 0.6