BAADER H-BETA 5.5nm FILTER
Baader Planetarium
BAADER H-BETA 5.5nm FILTER - 1¼" is backordered and will ship as soon as it is back in stock.
The Baader H-Beta 5.5nm filter is specifically designed for visual observation of faint emission nebulae under bright skies. Unlike H-alpha filters, which are extremely difficult to use visually due to the lack of sensitivity of our eyes at the deep red end of the spectrum, H-beta emissions are very close to where our eyes are most sensitive. Because of quantum-mechanical coupling with H-Alpha, you can see many of the same structures through an H-Beta filter. This makes it act like a visual H-Alpha filter.
Baader CMOS-Optimized filters - advantages
- Very high contrast due to steep edges of the coating
- Reflex-Blocker coatings to minimize reflections caused by correctors, reducers and other optical elements
- Standardized thickness for maximum possible parfocality - less need to refocus due to different filter thicknesses
- Blackened edges with front-side markings
- Each filter is individually fine-polished and coated with sealed coating edge, preventing moisture ingress
- Life-Coat for hardness and age-resistance, making the filters able to withstand tougher conditions for longer
For more information on Baader's new generation of CMOS-optimized filters, check out this blog post!
Specifications
| Transmission range |
H-Beta |
|---|---|
| Central wavelength |
486.1 nm |
| Half bandwidth | 5.5 nm |
| Suitable for f/ratio | f/15 to f/1.8 |
| AR-coating |
Reflex-Blocker hard coated, planeoptically polished |
| Filter thickness 1.25", 2", 31 mm, 36 mm | 2 mm (without cell), 6 mm with cell |
| Filter thickness 50.4 mm, 50 x 50 mm, 65 x 65 mm | 3 mm |
| Filter size | 1.25", 31 mm, 36 mm, 2", 50.4 mm round, 50 x 50 mm square, 65 x 65 mm square |
| SKU 1.25" | BA2961080 |
| SKU 31 mm | BA2961081 |
| SKU 36 mm | BA2961082 |
| SKU 2" | BA2961083 |
| SKU 50.4 mm round | BA2961084 |
| SKU 50 x 50 mm | BA2961085 |
| SKU 65 x 65 mm | BA2961086 |
