The Vespera light pollution filter or CLS (City Light Suppression) filter can help you improve the quality of your photos when observing in the city or suburbs. It attenuates the effects of light pollution and thus increases the contrast between the object photographed in the sky and the background sky. Essential for observing from an environment with high levels of light pollution (urban and suburban environments, residential lighting, etc.)Improves the quality of fog photography. The broadband filter blocks wavelengths of Na (sodium) and Hg (mercury), which are mainly from urban night lighting or unwanted natural light (atmospheric oxygen radiation, etc.) while it passes through the main wave lengths of celestial objects. The light pollution filter is particularly useful to improve the brightness of deep-sky objects: nebulae, star clusters, galaxies, etc. Because of the filtered wavelengths, it is particularly effective in emission nebulae. Features: CLS Filter for Vespera (AC023) Transparent storage box Dimensions: depth: 0.6 cm, width: 7.80 cm Color: Black (outside) Materials: glass, plastic Weight: about 15 g
