Solomark 1.25 Inch Telescope Moon and Skyglow Filter 1.25inch Moon and Skyglow Filter is Skyglow is a multi-bandpass filter transmitting a high percentage of light in the visual spectrum. The Moon & Skyglow is a multi-bandpass filter transmitting a high percentage of light in the visual spectrum. The filter enhances contrast when observing brighter objects including the moon and planets. The filter has a mild effect of darkening the background of the night sky so that the fainter objects are more clearly seen contrasted against the blackness of space. The filter effectively filters out selective wavelengths of low-pressure sodium and other man-made sources typically used in street lighting. Although it is not a nebula filter, it enhances the views of deep-sky objects by increasing the contrast of these objects against the background sky. The filter will fit all standard sized 1.25" eyepieces and accessories. It is mounted in a nicely anodized housing and is threaded on both sides for stacking with other filters if necessary.