Baader AstroSolar ASTF Filter

This filter is designed for telescopes with an outer diameter (O.D.) between 220mm and 260mm. You should measure the outer diameter of your telescope tube—not the aperture—to ensure it falls within this specific range before purchasing.

Yes, it is specifically engineered for safe solar observation. It is constructed with high-quality AstroSolar film that blocks harmful radiation, allowing you to view the sun's surface safely through your telescope.

The filter provides a neutral, high-contrast view of the sun. It typically renders the sun in a natural white light, allowing you to see solar details like sunspots and granulation with excellent clarity.

The filter itself mounts onto the front of your telescope tube, not the eyepiece. The 2-inch connection interface mentioned refers to specific mounting configurations, but your primary concern should be the front aperture fit for the telescope tube.

You should handle the filter carefully by the edges to avoid fingerprints. If cleaning is necessary, use only a specialized optical cleaning solution and a very soft, lint-free microfiber cloth, applying minimal pressure to avoid scratching the delicate film.