The Optolong H-Alpha 7nm CCD 2″ Mounted Filter is designed for astrophotographers seeking ultimate contrast and detail in emission nebulae imaging. With an ultra-narrow 7nm bandwidth centered on the 656nm H-alpha emission line, this filter isolates hydrogen signals while blocking unwanted light pollution, skyglow, and infrared interference.

Optimized for CCD and DSLR imaging, this filter delivers vivid, high-contrast results even from light-polluted skies. Whether used alone or in combination with OIII and SII filters for tricolor narrowband compositions, its an essential tool for deep-sky imaging. Built with high-quality Schott B260 glass and multi-layer ion-assisted coatings, the Optolong H-Alpha filter ensures stability, sharp transmission, and durable performance for years of astrophotography excellence.

• Filter Type: H-Alpha Narrowband
• Size: 50.8mm (2″)
• Filter Shape: Round
• Insert Style: Threaded
• Optical Thickness: 2.0 mm
• Wavelength (CWL): 656nm (H-alpha)
• Bandwidth: 7 nm
• Material: Schott B260 substrate glass
• Surface Quality: 60/40 (MIL-O-13830)
• Transmission:
  • >80% at H-alpha 656nm
  • IR Cutoff: 7001100nm
  • <0.1% at Hg 435nm / 578nm
  • <0.1% at Na 589nm