Lunt LS50THa H-alpha solar telescope, B400 PT The LS50THa is Lunt's most popular dedicated hydrogen-alpha telescope. Its internal etalon is pressure-tuned (Doppler True), shifting the bandpass smoothly and uniformly across the field so features can be scanned through the H-alpha line. An integrated clamshell base takes a Vixen dovetail, and the LS50C…
Manufacturer model: Lunt LS50THa H-alpha solar telescope, B400 PT · Specifications checked against manufacturer data on 2026-11-03
The LS50THa is Lunt's most popular dedicated hydrogen-alpha telescope. Its internal etalon is pressure-tuned (Doppler True), shifting the bandpass smoothly and uniformly across the field so features can be scanned through the H-alpha line. An integrated clamshell base takes a Vixen dovetail, and the LS50C front filter adds double stacking.
Always use the telescope with its Lunt blocking filter in place; it is a dedicated solar instrument in H-alpha configuration.
| Telescope type | Dedicated H-alpha (daytime solar use only) |
|---|---|
| Aperture | 50 mm, unobstructed |
| Focal length | 350 mm |
| Focal ratio | f/7 |
| Objective | Custom doublet optimised at 656 nm, ion-assisted narrowband AR |
| Etalon | Internal, Doppler True barometric pressure tuning; UV-grade fused silica |
| Etalon wavelength | 656.28 nm |
| Bandpass | <0.6 Å single stack; ~0.35 Å with LS50C |
| Blocking filter bandpass | 6 Å |
| Mounting | CNC clamshell with Vixen-style dovetail |
| Weight | About 1.4 kg (3 lb) |
| Blocking filter | B400 blocking filter, diagonal, 4 mm clear aperture |
| Focuser | 1.25" helical |
LS50THa with B400 blocking filter.
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