The H-Beta filter is a narrowband filter specially designed for visual observation like Horsehead Nebula California and Cocoon Nebulae in Dark Skies.
In Stock
| Model | SV132 |
| Type | H-Beta |
| Size | 2-Inch |
| Substrate | B270 |
| Substrate Thickness | 1.85mm |
| Wavelength Range | 400-700nm |
| CWL | 486nm±2nm |
| FWHM | 25nm±2nm |
| T peak | 90% |
| Blocking | OD3 @300-1100nm |
| Clear Aperture | 44mm |
| Surface Quality | 60/40 |
| Surface parallelism | 1/4λ |
| Parallelism | 30" |
| Net Weight | 13.2g / 0.47oz |
The H-Beta filter is a narrowband filter specially designed for visual observation. It is mainly aimed at the 486nm (blue) line spectrum nebula, removes the interference of other light, and improves the contrast. During observation, in order to see sufficient dark nebula, it is necessary to ensure a large enough luminous flux with a large-aperture telescope. Small-aperture telescopes are not recommended. It is suitable for observing the Horsehead Nebula in Orion and the California Nebula. Filter with metal 2" threads fits 2" eyepieces and diagonal barrels.