Optolong H-Alpha 7nm CCD 1.25" Mounted Filter

The Optolong H-Alpha 7nm CCD Filter (1.25") is a precision-engineered narrowband filter designed for astrophotographers seeking maximum contrast and signal clarity in emission nebulae. With a narrow 7nm bandwidth centered at 656nm, it isolates the hydrogen-alpha emission line while aggressively blocking artificial light pollution and skyglow, delivering rich detail from hydrogen-rich regions in the night sky.

This filter is particularly effective in urban environments, enabling astrophotographers to reveal faint structures in nebulae even under compromised sky conditions. While the 7nm width results in slightly more star visibility than narrower filters, it still delivers powerful suppression of background noise and extraneous light.

Crafted from fine-polished Schott B260 optical glass, the H-alpha filter features multi-layered ion-assisted coatings that ensure central wavelength stability, durability, and minimal scatter. The ultra-thin, laser-engraved 1.25" cell is machined from lightweight aero-metal and anodized for corrosion resistance, offering a 26mm clear aperture compatible with most standard imaging setups.

• Filter Type: Narrowband – H-Alpha
• Center Wavelength: 656nm
• Bandwidth (FWHM): 7nm
• Transmission: ~80% at H-Alpha
• Infrared Block: 700–1100nm
• Off-band Rejection: <0.1% at Hg (435nm, 578nm), Na (589nm)
• Filter Size: 1.25" (31.75mm)
• Clear Aperture: 26mm
• Substrate: Schott B260 Optical Glass
• Glass Thickness: 2.0mm
• Surface Quality: 60/40 (MIL-O-13830)
• Wavefront Accuracy: λ/4
• Parallelism: <30 arcseconds
• Coating Method: Electron-Beam Evaporation with Ion-Assisted Deposition
• Filter Cell: CNC-Machined, Sandblasted, Black Anodized Aluminum
• Warning: Not for Solar Observation
• Certifications: RoHS, TUV Rheinland, Bureau Veritas

• Optolong 1.25" H-Alpha 7nm Filter
• Protective Plastic Case with EVA Foam Interior