Double stack: Every SolarMax telescope also comes with double stack. This means that two etalon filters are fitted one behind the other. This reduces the half width of the light which passes through the H-alpha line to less than 0.5 Angstroms. Without double stack, the half width is less than 0.7 Angstroms. The half width is provided in the product name and in the telescope's technical information.
The smaller half width results in higher contrast. The Sun’s structures appear three-dimensional. The image is also darker and needs to be finely readjusted using the tuning system due to the filter’s smaller half width.
This etalon filter allows you to retrofit your SolarMax telescope with a second H-alpha filter (known as 'double-stacking'). The etalon is simply screwed onto the lens. With a SolarMax II telescope, you will need the matching adapter ring from the recommended accessories. Like the telescope's built-in filter, this etalon is also equipped with the RichView system, which allows fine tuning of the filter. An etalon filter must never be used without a blocking filter! But of course the blocking filter is already built-in to the SolarMax telescope.
RichView™ & T-Max tuning: The H-alpha filter is a so-called etalon. In the etalon, destructive interference of the incident light extinguishes most of the radiation in the visible spectral range. Only the desired wavelength of 656 nanometres passes through.
To ensure that this works, the width of the etalon must be set precisely and readjusted during observation. Point the telescope at the Sun and use the focuser to bring the edge of the Sun into sharp focus. Turn the large rotating ring of the RichView™ system until the structures on the Sun are visible in maximum contrast. You can then use the small Max Tuning wheel to tilt the Etalon slightly until the maximum image brightness is achieved.
