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Baader SII 2 Narrowband CMOS Optimized 6.5nm Filter SII 2 Narrowband Filter
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Baader SII 2" Narrowband CMOS Optimized 6.5nm Filter

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SKU: BAD-FCSIIN-2
$267.00

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Baader SII 2" Narrowband CMOS Optimized 6.5nm Filter

Baader Planetarium has designed this 2" SII precision-grade filter to provide astrophotographers an excellent complement to their imaging setup. This Baader Planetarium SII narrwoband filter is CMOS optimized with Life-Coat. This coating is a hard coating that will not peel, flake, and will not physically degrade even in the most extreme weather conditions. This coating is also designed to withstand repeated cleaning with fine optical cleaning equipment. This coating is so durable that Baader is confident it will last the life of the filter.

With 4 nm FWHM, this filter from Baader is highspeed and recommended for optical systems from f/10 to f/3.5. The filters are designed to allow for 1:1:1 exposures. This matches the typical CMOS quantum efficiency and s/n ratio. SII filters are suitable for imaging cosmic bodies like nebulae that are along the singly ionized sulfur (SII) wavelengths. This narrowband filter works well both in conditions of light pollution or dark skies! SII filters block all wavelengths from UV to infrared, including the emission lines of sodium/Na and mercury/Hg artificial lighting, except for the SII singly ionized sulfur wavelengths which occur as a doublet at 671.7 nm and 673 nm.

Not only do the filters have sealed coating edges with the Life-Coat, but they are also hard coated with Reflex-Blocker and planoptically polished. All of the edges are blackened for increased contrast and eliminate any reflection that would come from light falling on the edge of the filter. The filters are also equipped with a filter-lead-side-indicator in the form of a frontside outer rim. The filters are optimized for CMOS cameras and also work great with CCD cameras.

Baader Narrowband 2" CMOS Optimized Filter Features

  • Transmission Ranges: SII
  • Filter Thickness (w/out glass) 2 mm
  • Half Bandwidth: 6.5 nm
  • Central Wavelenth: 671.7 nm
  • AR-Coating: Reflex Blocker hard coated and planoptically polished
  • Filter Size: 2"
  • Threaded: Yes
  • Usage: CMOS, CCD, SII
  • Mounted: Yes
  • Filter Type: Narrowband
  • Filter Shape: Round
  • Feature Highlight: CMOS-Optimized with Life-Coat