The SVBONY 2" SII Filters are made of glass import from Germany that has been multi-coated with an ion-assisted deposition technology to ensure scratch resistance and stability on the central wavelength or CWL.
|transmission SII||80% at 672nm|
|Infrared wavelength||700-1100nm cut-off|
|transmission Hg||0.1% at 435nm and 578nm|
|transmission Na||0.1% at 589nm|
1. The Sulfur II 7nm Extra Narrowband Filter transmits a 7nm bandwidth of light that is centered at 672nm and drastically reduces other transmissions, including wavelengths of light that are responsible for light pollution (both artificial and natural). Like all SVBONY filters that are designated as “CCD”, this SII filter also blocks infrared wavelengths from 700nm to 1100nm so you don't need a separate IR-Cut filter
2. Thin metal cells have a clear aperture of 45mm for 2inch filters,each filter comes with a plastic case with high pressure EVA case lining