The anti-reflection filter is an accessory for the DSII/SFPT double-stack module for the Lunt Solar Systems LS80MT and LS100MT telescopes. Reflections that may occur there can be effectively reduced with this anti-reflection filter if necessary.
At the LS80MT and LS100MT multipurpose telescopes from Lunt Solar Systems, double-stacking is possible in H-alpha mode for solar observation with the internal DSII/SFPT double-stack modules (item number 0551395). The DSII modules reduce the bandwidth to <0.5 Angstroms. The DSII modules are designed to show better the surface details of the Sun, the contrast is significantly increased, and therefore filaments and active areas are better visible.
But the DSII modules can also induce reflections, which can show up as a strong brightening around the sun. This so-called ''glow'' is not a problem when observing the solar surface. But it can complicate the observation of prominences, and many observers find it disturbing. The HRG/SFPT anti-reflection filter is designed to solve this problem. The filter effectively reduces the reflections. But please also note that the image will become darker by using this anti-reflective filter.
The HRG/SFPT anti-reflection filter is easy to install. It is not necessary to return the telescope to the manufacturer, the filter can be easily installed by the user.
This filter cannot be used separately! It can only be used on a Lunt Solar Systems LS80MT or LS100MT telescope together with a DSII/SFPT Double-Stack module.