SVBONY W9121B 2-inch OIII-CCD 7nm Narrow-Band Filter for Deep Sky Mounted

Description
The SVBONY 2′ 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 45mm.
The Oxygen III 7nm Extra Narrowband Filter transmits a 7nm bandwidth of light that is centered at 500nm 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 OIII also blocks infrared wavelengths from 700nm to 1100nm so you don’t need a separate IR-Cut filter.
Quality Filter Materials
1. Material from Germany, 2.0mm thick
2. CNC machined and black anodized aero-metal filter cell that is ultra-thin to provide largest clear aperture; Laser-engraved to prevent fading
3. Multiple layers of anti-reflection non-cementing coatings applied via evaporation with Ion-assisted deposition
Filter Manufacturing Processes and Parameters
1. Filter substrate is fine-optically polished to 1/4 wave and
2. Surface quality, according to MIL-O-13830, is 60/40
3. 80% transmission at OIII line 500nm
4. Infrared wavelength 700-1100nm cut-off
5. 0.1% transmission Hg at 435nm and 578nm
6. 0.1% transmission Na at 589nm
7. Thin metal cells have a clear aperture of 45mm for 2 inch filters
8. Each filter comes with a plastic case with high pressure EVA case lining
Package includes
1 x SVBNOY 2′ OIII 7nm Filter
1 x PP Material Plastic Box
Details picture: