Chroma OII filter 8nm - 2″ mounted

8nm OIII filter from Chroma Technology

Visit 8nm OIII filter from Chroma Technology is a narrow-band filter designed for astronomical imaging. It is optimized to isolate the emission line of doubly ionized oxygen (OIII) at 500.7 nm, one of the most important emissions after H-alpha in the study of planetary and diffuse nebulae.

Key features

• Bandwidth : 8 nm, providing effective isolation of the OIII line while blocking unwanted wavelengths (light pollution, sodium and mercury lamps).
• High transmission : Up to 94.5 % at 500.7 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 minimize halos and stray reflections.
• Available formats :
  • Mounted: 1.25", 2".
  • Unmounted: Customized formats (31 mm, 36 mm).
• Substrate thickness : Approx. 3 mm, made from a unique optical glass substrate for exceptional durability.

Applications

• Imaging OIII-rich nebulae :
  • Ideal for capturing objects such as the Veil Nebula, Orion Nebula and Rosette Nebula.
• Reducing light pollution :
  • Effectively blocks unwanted wavelengths, even in urban or suburban environments.
• Advanced astrophotography :
  • The perfect complement to H-alpha and SII filters for scientific palette images (SHO or Hubble palette).
• Compatibility with high-speed systems :
  • Works perfectly with focal ratios up to f/4.0.
  • An optimized version is available for high-speed systems (f/2.6 to f/3.6) to compensate for blueshift.

Technical highlights

• Exceptional durability :
  • Sputter coatings guarantee long-term spectral stability.
  • Resistant to extreme variations in temperature and humidity.
• Anti-halos design : Anti-reflective coatings eliminate halos around bright stars, delivering sharp, detailed images.
• Universal compatibility : Compatible with most filter wheels and drawers on the market.

Conclusion

The filter Chroma OIII 8nm is an essential tool for deep-sky imaging. Its optical precision, high transmission and ability to effectively reduce light pollution make it an essential choice for capturing the subtle details of nebulae rich in ionized oxygen (OIII).