Lunt 40mm Double Stack filter for LS40THa

Lunt 40mm Double Stack Filter for LS40THa Preorder notice: ships 30–60 days after checkout (estimated window) Purpose-built LS40FHa front etalon to double-stack your Lunt 40 mm dedicated H-alpha telescope for a serious contrast boost No central obstruction and integral tilt tuning maintain even illumination and let you precisely dial features on-band Tighten your system from an estimated <0.70 Å (single stack) down to ~<0.50 Å (double stack) for finer filaments, mottling, and plage detail Blocking filter required for safe operation (Lunt BF, matched to your setup; sold separately) Drop-in upgrade that does not change the telescope’s focal length (400 mm remains unchanged) Lightweight, field-friendly design (~1 lb)—ideal for travel and quick outreach setups Store it with your scope: fits the optional LS40 aluminum hard case with fitted foam Specifications Model: LS40FHa Double Stack Solar Filter (for Lunt 40 mm dedicated H-alpha telescopes) Optical Aperture: 40 mm (front-mounted; no central obstruction) Bandpass (effective, double-stacked): ~<0.50 Å Bandpass (single-stack reference): <0.70 Å (host system prior to DS) Tuning: Tilt (integrally tuned) Telescope Focal Length (unchanged): 400 mm Weight: ~1 lb (~0.4 kg) Storage: Fits optional LS40 aluminum hard case with fitted foam Safety Requirement: Use only with a Lunt Blocking Filter appropriate to your system What’s in the Box? Lunt LS40FHa 40 mm Double Stack Etalon Unit Notes: A Lunt Blocking Filter (BF) is required and sold separately. This DS filter is designed exclusively for Lunt’s dedicated LS40 H-alpha telescopes.