Chroma H-alpha filter 8nm - 2″ Mounted

8nm H-alpha filter from Chroma Technology

Visit 8nm H-alpha filter from Chroma Technology is a narrow-band filter designed for astronomical imaging, particularly suited to capturing nebulae rich in ionized hydrogen. With a bandwidth of 8 nm centered on the H-alpha line at 656.3 nm, it is ideal for astrophotographers wishing to obtain detailed, high-contrast images, even under conditions of light pollution.

Key features

• Bandwidth : 8 nm, enabling precise isolation of the H-alpha line while blocking unwanted wavelengths.
• High transmission : Up to 96.05 % at 656.3 nm, guaranteeing an excellent signal-to-noise ratio for capturing subtle details.
• Optical quality :
  • Surface polished to an accuracy of λ/4.
  • Multi-layer anti-reflective coatings on both sides to prevent halos and stray reflections.
• Available formats :
  • Assembled: 1.25" and 2".
  • Unmounted: Custom formats available.
• Substrate thickness : Approx. 3 mm, made from a single substrate of high-quality optical glass for maximum durability.

Applications

• Imaging emission nebulae :
  • Ideal for capturing HII regions rich in ionized hydrogen, such as the Orion Nebula, the California Nebula or the Horsehead Nebula.
• Reducing light pollution :
  • Effectively blocks stray lines (sodium and mercury lamps) and sky background light.
• Compatibility with high-speed systems :
  • Works perfectly with focal ratios up to f/4.0. For faster systems (f/3), an optimized version is available.
• Advanced astrophotography :
  • Combine it with OIII and SII filters to produce SHO (Hubble Palette) images, or add RGB data to enrich natural colors.

Technical highlights

• Exceptional durability :
  • Sputtered hard coatings offer resistance to extreme variations in temperature and humidity.
• Anti-halos design : for sharp, artifact-free images around bright stars.
• Anti-vignetting design:
  • Compatible with modern sensors, including those with a diagonal of less than 31 mm (for 1.25" format).
• Easy integration :
  • Compatible with most filter wheels and drawers on the market (ZWO EFW, QHY CFW, etc.).

Conclusion

The filter Chroma H-alpha 8nm is an essential tool for deep-sky imaging, offering excellent contrast and high transmission. Its robust design and optical performance make it an essential choice for amateur or professional astrophotographers wishing to capture rich detail in emission nebulae.