Astronomik CLS Light Pollution Filter

While the CLS filter is highly effective at suppressing common artificial light sources like mercury and sodium-vapor streetlights, it cannot eliminate all light pollution. It significantly improves contrast and visibility, but you will still see some impact from extreme light sources.

Yes, this filter is designed for standard 2-inch telescope focusers and eyepieces. As long as your equipment supports 2-inch threaded accessories, it will integrate seamlessly into your setup.

The high 97% transmission rate ensures that the critical H-alpha light—which is essential for viewing nebulae and other deep-sky objects—passes through the filter with minimal loss. This allows you to retain detail and brightness that lower-quality filters might otherwise block.

This filter is excellent for both visual observation and astrophotography. It enhances the contrast of deep-sky objects, making them easier to spot through an eyepiece while also helping to clean up the background sky in long-exposure images.

Like any high-quality optical glass, you should handle the filter by its edges to avoid fingerprints. If cleaning is necessary, use a dedicated lens cleaning solution and a soft, lint-free microfiber cloth to gently wipe the surface.