The SVBONY H-Alpha is an extremely narrow emission-line filter that works by allowing a 5nm bandwidth of light, centered on the 656.3nm wavelength through, and blocking the transmission of contrast-killing light pollution wavelengths. Wavelengths that are responsible for natural light pollution, or skyglow, are drastically reduced, as is artificial light pollution caused by high- and low-pressure sodium vapor and mercury vapor lights. This H-Alpha filter also blocks infrared wavelengths from 700nm to 1000nm so you don't need a separate IR-Cut filter.
Please Note: This h-alpha filter is NOT for use on the Sun.
In Stock
Specifications
| Model | SV227 |
| Type | H-Alpha Filter |
| Size | 2-Inch |
| Wavelength Range | 300-1000nm |
| CWL | 656.3nm |
| FWHM | 5nm |
| Peak Transmittance | ≥90% |
| Substrate Thickness | 1.85mm |
| Wavelength Range | 300-1000nm |
| Blocking | ≥OD5 |
| Clear Aperture | 44mm |
| Surface Quality | 60/40 |
| Surface Pparallelism | 1/4λ |
| Parallelism | 30" |
| Thread | M48x0.75 |
| Single Thread | Yes |
| Net Weight | 12.5g / 0.44oz/0.027lb |
Features
- 1. H-Alpha CCD narrow band filter reduces other transmissions, including wavelengths of light that are responsible for light pollution (both artificial and natural)
- 2. 300-1000nm Wavelength Range; the SVBONY Sulfur II 5nm Extra Narrowband Filter transmits a 5nm bandwidth of light that is centered at 656.3nm
- 3. German imported glass; multiple layers of anti-reflection non-cementing coatings applied via electron-beam gun evaporation with Ion-assisted deposition
- 4. CNC machined and black anodized aero-metal filter cell that is ultra-thin to provide largest clear aperture; Laser-engraved to prevent fading
- 5. 2 inch mounted; metal filter cell threads directly into the 2 inch barrel of your telescope eyepiece