Baader S-II 2" unmounted f/2 Highspeed Filter 6.5 nm CMOS optimized (2961303U)

Baader S-II 2" unmounted f/2 Highspeed Filter 6.5 nm CMOS optimized (2961303U)

Description

The Baader S-II 2" unmounted (Ø 47.4 mm, 2 mm thick) f/2 Highspeed Filter 6.5 nm is designed for extremely fast optical systems like the Celestron RASA f/2 astrographs. It is specially selected for Baader FCCT (Filter Changer Camera Tilter) filter sliders, compatible with QHY cameras and other versions.

Optimized for CMOS sensors, it also performs excellently with CCD cameras. With a central wavelength of 671.7 nm and a 6.5 nm bandwidth, this filter isolates the sulfur-II emission line (S-II), making it essential for narrowband imaging and SHO (Hubble) palette astrophotography.

Featuring precision planeoptical polishing and Reflex-Blocker™ hard coating, it minimizes stray reflections. Blackened edges with telescope-side indicator ensure correct orientation, while Life-Coat™ sealed protection guarantees long-term durability. Lightweight (0.01 kg) and robust, this filter is sold individually and provides outstanding performance in S-II astrophotography with ultra-fast optics.

Technical Specifications

• Manufacturer: Baader Planetarium

• Product SKU: 2961303U

• EAN code: 4047825050991

• Net weight: 0.01 kg

• Filter type: S-II f/2 Highspeed

• Mount: unmounted

• Shape: round

• Diameter: 47.4 mm (2" without cell)

• Thickness: 2 mm

• Central wavelength (CWL): 671.7 nm

• Half bandwidth (HBW / FWHM): 6.5 nm

• Transmission: S-II line

• Coating: Reflex-Blocker™ hard coated, planeoptically polished

• Durability: Life-Coat™ sealed edges

• Edges: blackened with telescope-side indicator

• Suitable f/ratio: f/3.4 and faster

• Compatibility: Celestron RASA 8", Baader FCCT, QHY cameras, CMOS and CCD

• Application: S-II astrophotography, nebulae, SHO palette, deep-sky imaging

• Packaging: single filter