The Eyepiece Filter Set - 1.25" from Celestron contains 4 assorted filters mounted in black anodized aluminum cells, packed in a plastic case. All 4 eyepiece filters are threaded to fit Celestron's, and most other manufacturers 1¼" eyepieces. The cells of each filter are double-threaded so that they can be stacked in different combinations. They offer a full 26 mm clear aperture. This filter set includes: Orange #21, Light Blue #80A, Deep Yellow #15 and 25% #96ND filters.
Celestron's filters are made of high quality, solid plane parallel glass. They have an anti-reflection coating to help prevent glare and aberrations. Not only are these highly useful filters and combinations, but they also provide an economical way to add versatility to your filter collection.
#21 Orange 46% T
Moon - Greatly enhances lunar features. Jupiter - Improves appearance and detail revealed in structure of Jovian belts. Enhances viewing of festoons and polar regions. Mars - Reduces light from the blue and green areas which darken the maria, oases and canal markings, while lightening the orange-hued desert regions. Also sharpens the boundaries of yellow dust clouds. Mercury - Reduces the brightness of blue sky during daylight observing, to reveal surface features. Saturn - Improves structure of the Saturnian bands and highlights blue polar regions. Venus - Use during daylight observing to reduce brightness of blue sky. Comets - Enhances definition of comet dust tails and heads in larger telescopes (11" and greater aperture). Solar - When using a Celestron Mylar Solar Filter, adding this orange filter will give true color rendition.
#80A Light Blue 30% T
Moon - Enhance lunar detail. Jupiter - Enhance the boundaries between the reddish belts and adjacent bright zones. Useful for viewing the Great Red Spot. Mars - Very useful during the violet clearing. Helpful in studying surface features and polar caps. Mercury - Improve observation of dusky surface markings at twilight, when the planet is near the horizon. Saturn - Enhance low-contrast features between the belts and zones. Venus - Useful for increased contrast of dark shadings in upper Venusian clouds. Comets - Bring out the best definition in comet gas tails.
#15 Deep Yellow 67% T,
Moon - Enhances the lunar features. Jupiter - Penetrates and darkens the atmospheric currents that contain low-hue blue tones. It enhances the orange and red features of the belts and zones. It is useful for studies of the polar regions. Mars - Reduces the light from the blue and green areas which darken the marias, oases and canal markings while lightening the orange-hued desert regions. It also sharpens the boundaries of yellow dust clouds. Neptune - Will improve detail in larger telescopes such as an 11" or larger apertures. Saturn - Penetrates and darkens the atmospheric currents containing low-hue blue tones. It enhances the orange and red features of the belts and zones. Uranus - improves detail in larger telescopes such as an 11" or larger apertures. Venus - Reveals low-contrast surface features. Comets - Enhances the definition in comet tails.
#96 ND 25% T - Density 0.6
Moon - Excellent for reducing irradiation, glare and subject brightness. Colors are unaltered, as light is transmitted uniformly over the entire spectrum. Each model performs somewhat differently, depending on the brightness of the moon. Planets - Stacking in combination with color filters lowers transmission, but retains true color balance for specific applications. Reduces glare on brighter planets and minimizes irradiation. Binary (Double) Stars - Helpful in splitting binary stars, because it reduces glare and diffraction effects around the brighter star of the binary pair.