Lunt 60mm Ha Etalon Filter

Using the LS60FHa as a standalone filter requires a Lunt Blocking Filter, which must be purchased separately, and the appropriate adapter for your refractor. The blocking filter must be used at all times: it is a safety requirement, and it houses additional filters which are required for the safety and performance of the solar package. You must select a blocking filter appropriately sized for your telescope's focal length.

A single-stacked LS60MT provides excellent views, but double-stacking to achieve a <0.28Å bandpass increases contrast. Filaments appear darker and more defined against the solar disk, and subtle structural details that are washed out at a wider bandpass become easier to see.

The tilt-tuning mechanism physically angles the etalon relative to the incoming light. This slight tilt shifts the filter's central wavelength, allowing you to "tune" into the precise wavelength of solar features that may be slightly blue- or red-shifted due to their velocity relative to us (Doppler effect). This allows you to maximize contrast on specific active regions or filaments.

No. The LS60FHa has a clear aperture of 60mm. When placed on the front of any telescope, it acts as a 60mm aperture stop. Your 100mm refractor will perform as a 60mm H-alpha solar telescope, with its resolution and light-gathering ability limited to that of a 60mm instrument.

Installation is straightforward. The LS60FHa can simply be screwed onto the front of the LS60MT, and it is easily removable so the telescope can continue to be used for night observing.

It means that Lunt Solar Systems individually tests each LS60FHa etalon with precision metrology instruments to confirm it meets the 0.4Å specification. This provides assurance that you are receiving a filter that performs to the stated level of contrast, rather than one based on a design estimate or batch testing.