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Baader Planetarium Ultra Narrowband 4.5 nm SII CCD Filter - 31 mm - FSIINU-RD31

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Baader 31 mm Round Ultra Narrowband 4.5 nm SII CCD Filter

Optimized for fast telescope optical systems with f/8 to f/3.5 focal ratios, this 31 mm round formatted Ultra Narrowband filter from Baader Planetarium provides users with a convenient entry point into the world of extremely narrow 4.5 nm SII CCD imaging. Enhanced ionized sulfur (SII) contrast emphasizes faint details in nebula while simultaneously suppressing more stars. Features smooth internal surfaces and anti-reflective coatings.