Optolong S-II Deep-Sky Filter 6.5 nm, 2" Filter Cell

Optolong S-II Deep-Sky Filter 6.5 nm, 2" Filter Cell

Extra Narrowband SII-CCD 6.5 nm filter is designed for nebula observation allowing 6.5 nm bandwidth of light centered on a wavelength of 672 nm through, which corresponds to the [S II] emission line, 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 (skyglow).

Main Use and Performance

• Suitable for photographing on faint emission nebulae in full moonlight or in severe light pollution
• Hubble look of images can be made by the combination of H-alpha, OIII-CCD and SII-CCD, such as the famous Pillars of Creation (M16 Eagle Nebula)
• Narrowband imaging with SHO set (H-alpha, OIII-CCD and SII-CCD) can be done with the moon up in heavy light pollution, so your equipment is not sitting dormant for several weeks