Lunt 50mm Center Obstructed H-Alpha Filter Set
More Aperture For Your Existing Refractor
This 50mm center obstructed H-alpha set from Lunt clamps over the centre of your refractor objective and turns it into a solar instrument. The 50mm etalon gathers more light than the 40mm version, so the disc looks brighter and fine detail in filaments and active regions holds up better at higher magnification.
Bandpass is rated below 0.65 Angstrom at 656.28 nm and tuning is by tilt, so you simply angle the housing until the passband sits on the line. There are no pumps or pressure controls. A centre mounted foot carries the etalon, which places a central obstruction in the clear aperture.
You choose a B600 or a B1200 blocking filter, and one adapter plate is included in the set. Nine plate sizes run from 55 to 60 mm up to 95 to 100 mm in 5 mm steps, covering objective housings up to 4 inches. The size you need is set by the outside diameter of your dew shield, so to measure for your adapter plate take a measurement of the outside diameter of the dew shield on your refractor telescope. Give that figure at checkout and the matching plate ships with the filter.
Key Features
- Front Mounted - fits over the centre of an existing refractor objective and comes off again in seconds
- Fifty Millimetre Etalon - more light grasp than the 40mm set for brighter views and finer detail
- Bandpass - rated below 0.65 Angstrom at the 656.28 nm hydrogen alpha line
- Tilt Tuned - angle the housing to centre the passband, with no pressure system to manage
- Nine Adapter Plates - one plate for dew shield outer diameters from 55 mm to 100 mm is included in the set
- Centre Obstruction - the etalon is held by a central foot, so the aperture is obstructed at the middle
| Specifications | |
|---|---|
| Type | Front mounted center obstructed hydrogen alpha etalon filter set |
| Etalon Aperture | 50 mm, center obstructed by the support foot |
| Wavelength | Hydrogen alpha, 656.28 nm |
| Bandpass | Less than 0.65 Angstrom |
| Tuning | Tilt tuned |
| Blocking Filter Options | B600 with 6 mm clear aperture, or B1200 with 12 mm clear aperture |
| B600 Suitability | Lunt lists the included B600 for focal lengths up to 540 mm |
| B1200 Suitability | Lunt lists the B1200 for visual use to 1080 mm and imaging to 540 mm |
| Adapter Plate | One plate included with the set, chosen at checkout |
| Adapter Plate Sizing | Measured on the outside diameter of the dew shield on your refractor, ranges 55-100 mm |
| Adapter Plate Sizes Published | 55-60, 60-65, 65-70, 70-75, 75-80, 80-85, 85-90, 90-95 and 95-100 mm, taken on the dew shield outer diameter |
| Adapter Plate Codes | LS50-CO-AP5560 through LS50-CO-AP95100 |
| Objective Cell Limit | Objective housings up to 4 inches |
| Use | Visual and imaging |
| Model / SKU | LS50F-CO-B600 and LS50F-CO-B1200, plus adapter plate codes LS50-CO-AP5560 through LS50-CO-AP95100 |
| Storefront Listing | Published as Lunt LS50C Hydrogen-Alpha Front-Mounted Etalon System B600 and B1200 |
| Shipping Weight | Not published |
| Warranty | 5 years from date of purchase, original purchaser, manufacturing and workmanship defects |
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