Baader Filters SII CMOS f/2 Highspeed 1.25″

The Baader Filters SII CMOS f/2 Highspeed 1.25″ is designed specifically for modern CMOS cameras and high-speed optical systems such as RASA and HyperStar. This filter is precisely matched to the SII emission line (672.4 nm) and optimized for f/2 light cones. This keeps the transmission perfectly at wavelength, with no shift or light loss in fast systems.

The Baader hard coating technology ensures maximum durability and prevents reflections, halos and oxidation. Thanks to the high transmission (>90%) within a bandwidth of about 6.5 nm, weak SII signals in emission nebulae become clearly visible even under light-polluted conditions.

Together with the Hα and OIII filters, this SII filter forms an ideal narrowband trio for Hubble palette images (SHO). The results provide high-contrast, scientifically accurate color compositions of nebulae such as the Pelican Nebula, Veil Nebula and Rosette Nebula.

Application:
Perfect for narrowband astrophotography with CMOS cameras and fast telescopes up to f/2.
Ideal for:

• SII structures in emission nebulae
• RASA and HyperStar systems
• Deep-sky projects with Hα and OIII combination

Specifications:
Filter type: SII narrowband (CMOS f/2 Highspeed)
Central wavelength: 672.4 nm
Bandwidth (FWHM): ±6.5 nm
Transmission:>90%
Barrel size: 1.25″
Coating: Hard, anti-reflection
Compatible: CMOS cameras, f/2 optics
Country of origin: Germany