Lunt LS50C Compact Double-Stack Filter

LS50C — Compact Double Stack Filter The double-stack upgrade designed specifically for the Lunt LS50THa 50mm solar telescope series.

Now with new-generation etalons — every unit individually tested on Lunt's precision metrology equipment. Every specification is verified, not estimated.

The LS50C is a compact double-stack filter made specifically for the Lunt LS50THa 50mm dedicated solar telescope series. It threads directly onto the front of the LS50THa OTA in seconds — no tools, no factory visit — adding a second 0.35Å tilt-tuned etalon to the optical path and reducing combined system bandpass to ~0.30Å when used with current LS50THa telescopes.

The compact form factor is the defining characteristic of the LS50C. It is designed to maintain the LS50THa's grab-and-go character — the total system with the DS filter in place remains compact and manageable on any Vixen-compatible mount or photo tripod. At ~0.30Å combined bandpass the chromospheric contrast improvement over single-stack is immediately and dramatically visible. Surface structure that single-stack views render as texture becomes resolved detail. Plage regions separate from the chromospheric background. Filaments show dark cores and complex multi-strand architecture. Prominences reveal internal threading from base to tip.

Note: A Lunt blocking filter is required for safe operation — the LS50C cannot be used without one.

Note on bandpass: Combined system bandpass of ~0.30Å is achieved when paired with current LS50THa telescopes. Future LS50THa instruments with new-generation internal etalons will achieve <0.28Å combined.

Specifications

• Model: LS50C
• Optical Aperture: 50mm compact — no central obstruction
• Tuning: Tilt-tuned
• Single Etalon Bandpass: 0.35Å — individually verified
• Combined System Bandpass: ~0.30Å with current LS50THa telescopes
• Installation: Threads directly onto LS50THa OTA front — no tools required
• Compatible With: LS50THa Standard, Enhanced, and Premium series
• Blocking Filter Required: Yes — sold separately (B600 recommended)
• Storage: Aluminium hard case with fitted foam