The Lunt H-Alpha solar telescopes can be retrofitted with double stacking modules. These DSII modulesreduce the half-width to <0.5 Angstrom: The contrast is significantly increased, making filaments and active regions more visible.
However, the DSII modules also cause reflections, which are noticeable as a brightening around the sun. This so-called "glow" is not a problem when observing the sun's surface. However, it can make it difficult to observe protuberances, and many observers find it disturbing.
This Antireflex filter solves this problem. The filter can be easily installed by the user; instructions are included.
Please note: This filter can only be used on a Lunt Solar Systems LS100T Ha solar telescope in combination with a DSII Double Stack Module.