SVBONY 1.25in SII-CCD 7nm Narrowband Filter Astronomical Photographic CCD Filter

Description

The SVBONY 1.25" Filters are made 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. The filter cell is made of lightweight, strong metal and is CNC machined, sand-blasted; black anodized, and then laser engraved. The result is a super thin filter cell that will produce a clear aperture of 26mm. 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 300nm to 1000nm so you don't need a separate IR-Cut filter.
Features:
Filter substrate is fine-optically polished to 1/4 wave and <30 parallelism over both surfaces
CNC machined and black anodized aero-metal filter cell that is ultra-thin to provide largest clear aperture; Laser-engraved to prevent fading
Multiple layers of anti-reflection non-cementing coatings applied via electron-beam gun evaporation with Ion-assisted deposition
Material from Germany, 1.85mm thick
Surface quality, according to MIL-O-13830, is 60/40
80% transmission at SII line 672nm
Infrared wavelength 400-700nm cut-off
Thin metal cells have a clear aperture of 26mm for 1.25 inch filters
Each filter comes with a plastic case with high pressure EVA case lining
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