Lunt 50mm Full Aperture H-Alpha Etalon Filter Set
Full Aperture 50mm Etalon For Your Refractor
This 50mm full aperture H-alpha etalon package from Lunt puts an unobstructed 50mm tilt tuned etalon in front of your refractor. Every etalon is individually tested on Lunt metrology equipment and rated at 0.4 Angstrom, so the bandpass on your unit is verified rather than estimated. Prominences, filaments and active region structure all show clearly.
Unlike the center obstructed sets, the full 50mm aperture stays clear, which helps resolution and evenness of illumination across the disc. Tilt tuning shifts the passband across the hydrogen alpha line at 656.28 nm, and the filter lifts off in seconds so the same refractor returns to night sky work after sunset.
The filter set is specified with a blocking filter matched to your focuser and focal length, in either a 2 inch or a 1.25 inch fitting. A B600 suits focal lengths to 540 mm, a B1200 to 1080 mm visually, a B1800 to 1620 mm, and a B3400 covers the longest focal lengths and large sensor full disc imaging.
Key Features
- Verified Bandpass - each etalon is tested individually and rated at 0.4 Angstrom rather than estimated
- Full Aperture - the 50mm clear aperture has no central obstruction from a support foot
- Tilt Tuned - angle the housing to centre the passband on the 656.28 nm line
- Blocking Filter Sizes - supplied as B600, B1200, B1800 or B3400 to suit your focal length
- Focuser Fit - the trailing 2 or 1 in the code sets a 2 inch or 1.25 inch blocking filter fitting
- Double Stack Ready - pairs with a Lunt LS60MT in series for a combined bandpass under 0.28 Angstrom
| Specifications | |
|---|---|
| Type | Front mounted full aperture hydrogen alpha etalon filter set |
| Etalon Aperture | 50 mm, no central obstruction |
| Wavelength | Hydrogen alpha, 656.28 nm |
| Single Etalon Bandpass | 0.4 Angstrom, individually verified |
| Double Stack Bandpass | Less than 0.28 Angstrom in series with the LS60MT internal pressure tuned etalon |
| Tuning | Tilt tuned |
| B600 Blocking Filter | 6 mm clear aperture, visual use to 540 mm focal length |
| B1200 Blocking Filter | 12 mm clear aperture, visual to 1080 mm and imaging to 540 mm |
| B1800 Blocking Filter | 18 mm clear aperture, visual to 1620 mm and imaging to 1080 mm |
| B3400 Blocking Filter | 34 mm clear aperture, visual to 3400 mm and imaging to 1800 mm, 2 inch straight through tube only |
| Focuser Fitting | Codes ending in 2 supply a 2 inch blocking filter, codes ending in 1 supply 1.25 inch |
| Blocking Filter Required | Yes, a Lunt blocking filter must remain in the optical path at all times |
| Storage | Aluminium hard case with fitted foam |
| Filter Weight | Lunt lists approximately 2 lb for the etalon assembly |
| Storefront Listing | Published as Lunt LS50FHa Front Mount 50mm Double Stack Solar Filter, etalon only, blocking filter sold separately |
| Model / SKU | LS50FHa2/B600, LS50FHa1/B600, LS50FHa2/B1200, LS50FHa1/B1200, LS50FHa2/B1800, LS50FHa1/B1800, LS50FHa2/B3400 |
| Shipping Weight | 10 lb |
| Warranty | 5 years from date of purchase, original purchaser, manufacturing and workmanship defects |
Manuals
Product Manual (PDF)Talk to a Specialist