Unlock High-Contrast Deep-Sky Astrophotography
The SVBONY H-Alpha 7nm 31.75 mm (1.25 in) Narrowband Filter (SKU: F9169A) is an essential tool for monochrome CCD and CMOS astrophotography. By isolating the critical hydrogen-alpha emission line at 656.3 nm with a tight Full Width at Half Maximum (FWHM) bandwidth of 7 nm, this filter dramatically boosts image contrast when capturing diffuse emission nebulae, planetary nebulae, and supernova remnants.
Superior Light Pollution Suppression & IAD Coating
Designed to perform even under city skies afflicted by severe artificial light pollution or during full moon phases, the filter blocks unwanted spectral lines from 300 nm to 1100 nm. It completely cuts off interference caused by low- and high-pressure sodium (Na) lamps and mercury (Hg) vapor streetlights.
Utilizing Ion-Assisted Deposition (IAD) multi-coating technology, the optical coatings achieve extreme atomic density. This minimizes wavelength thermal drift caused by ambient temperature changes during long exposure imaging sessions night after night.
7 nm FWHM Passband
High-efficiency transmission (>85%–90%) at 656.3 nm H-Alpha wavelength.
Precision Optical Glass
Features double-sided fine polishing achieving a surface flatness of 1/4λ and optical parallelism under 30 arcseconds (<30") to preserve pin-point star profiles.
CNC Anodized Housing
Machined from aircraft-grade aluminum alloy with anti-reflective internal extinction treatment and standard M28.5*0.6 filter threads.
Technical Specifications
| Parameter | Value / Detail |
|---|---|
| Brand & Model | SVBONY H-Alpha 7nm 1.25" Filter (SKU: F9169A) |
| Filter Diameter | 31.75 mm (1.25 in) |
| Glass Thickness | 1.85 mm (0.073 in) |
| Passband Center Wavelength | 656.3 nm (H-Alpha hydrogen emission line) |
| Bandwidth (FWHM) | 7 nm |
| Peak Transmittance | >85%–90% at 656.3 nm |
| Blocking Range | 300 nm – 1100 nm (Mercury & Sodium cutoff) |
| Surface Flatness | 1/4λ (λ/4) |
| Parallelism | < 30" (arcseconds) |
| Coating Technology | Multi-layer Anti-Reflection Ion-Assisted Deposition (IAD) |
| Thread Specification | M28.5 * 0.6 standard 1.25" filter thread |
| Cell Material | CNC-machined aluminum alloy with anodized matte extinction finish |
Package Contents
- 1x SVBONY 31.75 mm (1.25 in) H-Alpha 7nm Filter
- 1x Protective PP Plastic Storage Case with EVA Damping Foam Insert
Frequently Asked Questions & Important Warnings
| Brand | SVBony |







