OPTOLONG 1.25inch Filter SII-CCD 6.5nm Narrow-Band Filter for Telescope For Sale
When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
OPTOLONG 1.25inch Filter SII-CCD 6.5nm Narrow-Band Filter for Telescope:
$159.00
OPTOLONG 1.25 inch Filter SII-CCD 6.5nm Narrow-Band Filter for Astronomy Telescope Deep Sky 1.25" Mounted
The Optolong 1.25" Filters are made with Schott glass 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 Optolong Sulfur II 6.5nm Extra Narrowband Filter transmits a 6.5nm 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 Optolong 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.Quality Filter Materials: Schott B260 substrate material from Germany, 2.0mm thickCNC machined and black anodized aero-metal filter cell that is ultra-thin to provide largest clear aperture; Laser-engraved to prevent fadingMultiple layers of anti-reflection non-cementing coatings applied via electron-beam gun evaporation with Ion-assisted depositionFilter Manufacturing Processes and Parameters: Filter substrate is fine-optically polished to 1/4 wave and <30 parallelism over both surfacesSurface quality, according to MIL-O-13830, is 60/4080% transmission at SII line 672nmInfrared wavelength 700-1100nm cut-off0.1% transmission Hg at 435nm and 578nm0.1% transmission Na at 589nmHigh value transmission of pass-band and optical density of off-band is assured through Optolong's planetary rotation system, a homogenous and precise coating procedureThin metal cells have a clear aperture of 26mm for 1.25" filtersEach filter comes with a plastic case with high pressure EVA case lining Packageing:
- OPTOLONG 1.25 inch SII 6.5nm Filter
- Plastic Cases