Περιγραφή
Extra Narrowband SII 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
- narrowband line filter for important nebulae emission line
- well suited for cameras with full-frame transfer sensors
- 2 mm thick and thus homofocal with many other filters from Optolong
- interference filter
- 2″ thread
- fine-optically polished
- multi-layer hard coated – largely scratch-proof
- The third image is shown only for demonstration purposes, it shows the color a bit better.