Planetary filters - Set of 4 filters. These filters attach to the eyepieces and provide valuable assistance when observing the moon and planets. They significantly reduce glare and light scattering, increase contrast and clarity in planetary details, while reducing eye fatigue. They are made from high-quality homogeneous and optically flat glass. They feature special coatings that prevent light diffusion and double images.

All eyepiece filters have a thread suitable for 1¼" eyepieces of Celestron and most other manufacturers, offering a clear diameter of 26mm. Celestron's color filters are mounted in black anodized aluminum rings, with the Kodak Wratten serial number engraved on the side and are available in sets of four different colors, placed in plastic cases.

The filter rings have two threads (male-female), so they can be screwed onto each other in various combinations. This feature allows the creation of combinations that provide new color and different light transmission, or the same color with lower light transmission. When combining multiple color filters, the resulting transmission of the combination equals the product of the individual spectral transmissions of the filters you use. The effectiveness of the filters depends on various factors, such as the diameter and focal length of the telescope, the magnification used, and the seeing conditions.