Extra narrowband SII-CCD 6.5nm filter (Sulful II for CCD) is designed for nebula observation allowing 6.5nm bandwidth of light centered on a wavelength of 672nm through, and reducing the transmission of certain wavelengths of light, specifically those produced by artificial light including mercury vapor, and both high and low pressure sodium vapor lights and the unwanted natural light caused by neutral oxygen emission in our atmosphere (i.e. skyglow).

Bester H-alpha-Linienfilter für die Astrofotografie von Emissionsnebeln mit höchstem Kontrast und der Wiedergabe zartester Nebeldetails.

♦ schmalbandiger (<=7 nm) Linienfilter für wichtige Nebellinie
♦ bevorzugt für CDD-Kameras mit Full-Frame-Transfer-Technik
♦ 2 mm dick und somit homofokal mit vielen anderen Filtern von Optolong
♦ Interferenzfilter
♦ feinoptisch poliert
♦ mehrschichtig hartvergütet - reflexfrei und weitgehend kratzfest

The H-ALPHA 7nm filter is the most popular narrow-band filter that allows a 7nm bandwidth centered on a 656nm wavelength.

Extra narrowband SII-CCD 6.5nm filter (Sulful II for CCD) is designed for nebula observation allowing 6.5nm bandwidth of light centered on a wavelength of 672nm through, and reducing the transmission of certain wavelengths of light, specifically those produced by artificial light including mercury vapor, and both high and low pressure sodium vapor lights and the unwanted natural light caused by neutral oxygen emission in our atmosphere (i.e. skyglow).