ZWO 1.25" Duo-Band Filter

The ZWO 1.25″ Duo-Band Filter is a specialized narrow-band filter designed to combat the effects of light pollution. It is an excellent tool for deep-sky astrophotographers using one-shot color (OSC) cameras or monochrome cameras in areas with significant light pollution. This filter simultaneously captures the most important emission lines from nebulae: the H-alpha (656.3 nm) and Oxygen III (500.7 nm) lines. By isolating these specific wavelengths and blocking a vast majority of other light, it dramatically increases the contrast of nebulae against the background sky, allowing you to produce vibrant, detailed images even from a city or suburban backyard.

• Thread Size: 1.25″
• Passbands: H-alpha (656.3 nm) and O-III (500.7 nm)
• FWHM: H-alpha: 15 nm, O-III: 15 nm
• Substrate Material: Schott glass
• Coatings: Multi-layer anti-reflection coatings
• Primary Use: Light pollution rejection for emission nebulae
• Compatibility: One-shot color cameras and monochrome cameras with 1.25″ filter threads

• ZWO 1.25″ Duo-Band Filter
• Protective Plastic Case