ERF pre-filter E-130N100 for H-alpha solar monitoring | DayStar

If you want to view the Sun in H-alpha with a telescope with a larger aperture, a lot of heat will end up in the narrow band filter at the back. The DayStar ERF E-130N100 captures that at the front. This energy rejection filter blocks most of the ultraviolet and infrared light and lets through mostly red light, so an H-alpha filter like the DayStar Quark will have less to deal with.

The filter is located in front of the opening of your telescope, on the tube or the dew cap. A Quark is often used on a refractor. If you are still looking for a tube for that, please see our Refracting telescopes.

Measure the outer diameter of the tube or dew cap and compare it with the fitting. The filter should fit tightly and without gaps. Never look directly at the sun through an ERF alone, because it is only safe when part of a complete H-alpha setup. Also read How to view the sun safely.

If this size does not fit your tube, please check the ERF pre-filter E-140N100.