Svbony SV240 Multi-Narrowband Galaxy & Nebula NIR 2" is a professional astronomical filter designed to enable astrophotography in the immediate vicinity of the city. Thanks to its excellent ability to cut out light pollution in a wide spectral range, this filter allows for signal recording even with light pollution at a level of 8 on the Bortle scale.
This filter combines the ability to almost completely eliminate the unwanted component from sodium and mercury lamps with high transmittance for the Hα, O-III and Hβ spectral lines, which are among the most important from the point of view of astrophotography. It was made on a high-quality optical glass substrate that guarantees the stability of the filter's operation and its high durability.
Note! The Svbony SV240 Multi-Narrowband Galaxy & Nebula NIR 2" filter is not recommended for visual or solar observing.
• 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
• filter type: multiband filter
• Filter diameter: 2"
• Optical diameter (filter aperture): 44 mm
• filter thickness: 2 mm
• 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: M48x0.75
• weight: 12.5 g
• Svbony SV240 Multi-Narrowband Galaxy & Nebula NIR 2" filter
12 months
