Athabasca

Athabasca Circular Starry Night Filter is used for Night Cities, Galaxies and so on.

Athabasca Circular Starry Night Filter, does not increase the natural light and nebula brightness, but cut off certain types of artificial light (mainly Na and Hg). Other wavelengths, especially the spectrum of emission nebulae, are allowed to pass through. Hence, increases the contract of the nebula. However, not all light pollution can be cut off, such as the headlights (xenon) and still broadband light sources cannnot be effectively stopped.