Skip to content



  • 100mm front-mounted minimally obstructed hydrogen-alpha filter for use on a wide range of telescopes!
  • Connect the Lunt LS100FHa to your telescope with the appropriate adapter (sold separately), or use it to double-stack on an existing Lunt 100mm solar telescope or filter for a ~<0.5A band pass!
  • Choose the appropriate LS100FHa and blocking filter for your telescope’s focal length and focuser size.

Required Accessories: Typically an adapter plate will be required to attach a Lunt Solar Filter to the front of a customer-supplied telescope. These adapters are in stock for the more common user scopes, but can be custom-made to your specific requirement. An adapter is needed to add a LS100/DS module to a LS100FHa.

LS100FHa Solar Filter

The Lunt LS100FHa Solar Filter is a 100 mm aperture with a Root 3 non-centralized obstruction integrally tuned etalon for use on a customer-supplied refractor.

The standard system includes the B600 blocking filter, which provides full disk images on telescopes with up to 540 mm of focal length. Larger blocking filters suitable for longer focal length telescopes are also available options.

These Hydrogen-alpha filters are designed to retrofit (adapters required) the customer-supplied telescope for use during the day. They are easily removable so that the scope can continue to be used for night observing.

LS100FHa Solar Filter systems must include a front-mounted filter and a rear mounted 2″ or 1.25″ blocking diagonal. Be sure to use a blocking filter that best suits your telescope and your focuser size:

  • B600 – Up to 540 mm focal length, offered in 1.25″ or 2″ diagonal
  • B1200 – Up to 1080 mm focal length, offered in 1.25″ or 2″ diagonal
  • B1800 – Up to 1620 mm focal length, offered in 1.25″ or 2″ diagonal
  • B3400 – Up to 3060 mm focal length, offered in 2″ straight-through tube

Because the LS100FHa Solar Filter has an estimated bandpass of <0.70 Angstroms it is capable of providing high contrast views of both surface and edge detail. Adding an additional etalon system (double-stacking) will reduce the bandpass to ~<0.50 (dependent upon scope) allowing for higher resolution viewing and/or imaging. The part number LS100FHa is offered for this purpose or for those who already have a Lunt blocking filter. A Lunt blocking filter must be used with Lunt Ha filters at all times.


Single Stack Specifications
  • Optical Aperture: 100 mm
  • Etalon: Internal <0.7 Angstrom
  • Tuning: Tilt
  • Storage: Aluminum finished hard case with fitted foam
  • Weight: 8 lb