Used Generic Lunar and Planetary Filter Set, 1.25" - 7 filters

Condition:

This is a set of generic lunar planetary filters in excellent condition with clean optics.  There is a total of 7 filters in this set:  82A, 56, 23A, 21, 12, a polarizing filter 3 (one piece), and a green lunar filter.  This includes a jewel case and cardboard sleeve for each filter except the green lunar filter, which comes in its own cardboard box.  

Description: 

• A nice beginner’s set of 1.25” planetary filters for any telescope.
• See features on the Moon & planets in a whole new light.
• The aluminum cell is threaded on top and bottom for stacking.

Features

Colored filters can be used to bring out details on a planet’s surface or its cloud structure. All of the planetary filters included in the Celestron Lunar and Planetary Filter Set can be used on any 1.25” eyepiece with the proper filter threads, so they are very versatile. Just screw one onto the eyepiece of choice and slide it into the focuser.

This filter set includes the following colors:

23A Light Red - useful when observing Mercury and Venus during the day and at twilight and when observing Mars, Jupiter, and Saturn with telescopes 4" in aperture and larger.  Moon - Somewhat useful for improving contrast between lunar features in scopes 8" and larger.  Mercury - Improves observations at twilight, when the planet is near the horizon. Reduces brightness of terrestrial sky to enhance daylight observing. Venus - Reduces brightness of terrestrial sky in daylight observing, allowing occasional terminator deformations to be seen.  Mars - Filters out scattered blue light in the Martian atmosphere to Increase the contrast and definition of polar caps, frost areas, low clouds, and dust storms against the ochre deserts, particularly when Mars is close to Earth's horizon, as the red light it passes is the least refracted by air currents in our atmosphere. Reduces light from blue and green areas which darkens the maria, oases, and canal markings, while lightening the orange-hued desert regions. Sharpens the boundaries of yellow dust clouds.  Jupiter - Brings out structure in the belts and enhances festoons and polar regions.  Saturn - Useful on Saturn for studying the bluer cloud bands and polar regions.  Comets - Enhances the definition of comet dust tails in 10" and larger scopes.  25% transmission

56 Light Green - Moon - Useful for enhancing the contrast of lunar features in scopes 6" and smaller. Venus - Useful for Venusian cloud pattern studies and to reduce the brightness of the terrestrial sky during daylight observing of Venus (an excellent time to observe this planet, as the high contrast of Venus against the dark night sky often makes for uncomfortable and unsatisfactory observing, while during the day the contrast range is not nearly as great, irradiation within your eye is reduced, and subtle Venusian features are sometimes more visible). Mars - Excellent for increasing contrast of Martian polar caps and surface frosts with scopes 6" and smaller. Jupiter - Increases the visibility of the Great Red Spot (which is more like a Faint Red Spot at the present time) with scopes 6" and smaller. Useful for observing the low-contrast hues of red and blue visible in the Jovian atmosphere. Enhances white features in the planetary atmosphere. Saturn - Enhances white features in the planetary atmosphere. 53% transmission.  

The #21 Orange filter sharpens the boundaries along the plains of Mars due to the reduction of blue/green transmissions. Use on Jupiter and Saturn to enhance detail in the belts and polar regions.

The #12 Yellow Filter increases the contrast of blue and green areas on Mars, thus darkening the Maria, oases and canal markings, while lightening the orange-hued desert regions. It sharpens boundaries of yellow dust clouds and the blue clouds in the Martian atmosphere and is thus a favorite for viewing the red planet.

The #82A Light Blue filter enhances low-contrast details on the Moon, Mars, Jupiter, and Saturn without significantly dimming the image. It works by increasing contrast in atmospheric features and cloud belts and is often used by observers to highlight subtle surface details on Jupiter and Saturn.  

This set also includes a filter labelled "polarizing filter #3" (which is one piece), and a filter labelled "BG Moon Filter", which is light green.  

Each 1.25” filter has 26 mm of clear aperture, and is mounted in a black anodized aluminum cell that is threaded on both sides. Double threads allow the user to stack different filters together to create a custom color or affect the transmission percentage. Special coatings on each filter protect against reflections, ghosting, and scratches. A plastic case is included to keep your filters safe when not in use.