Celestron Eyepiece Filter Set 1-1/4 (23A,38A,58,ND-50)

by Celestron

Product Details

• Product Dimensions: 8 x 8 x 6 inches ; 2.4 ounces
• Shipping Weight: 1 pounds
• ASIN: B00008Y0TX
• Item model number: 94119-30
• Amazon Best Sellers Rank:
  • #63 in Camera & Photo > Accessories > Telescope Accessories > Filters
• Date first available at Amazon.com: March 19, 2003

Product Description

From the Manufacturer

Eyepiece filters are an invaluable aid in lunar and planetary observing. They reduce glare and light scattering, increase contrast through selective filtration, increase definition and resolution, reduce irradiation, and lessen eye fatigue. Celestron's filters are made of high-quality, solid plane parallel glass with excellent homogeneity. They're anti-reflection coated to prevent glaring and ghosting. All eyepiece filters are threaded to fit Celestron's, and most other manufacturer's, 1-1/4-inch eyepieces, and offer a full 26mm clear aperture.

Celestron color filters are mounted in black anodized aluminum cells with the Kodak Wratten Series Number individually engraved, and come available in assorted kits packed in plastic cases. The cells of each filter are double-threaded, so they can be stacked (piggybacked) in various combinations. This allows you to create different color combinations and transmission characteristics, or to have the same color characteristic, but with a lower transmission. When stacking color filters, the effective transmission of the combination you create is equal to the product of the spectral transmission of each of the filters used.

The effectiveness of the filters depends on several factors, including: the aperture and focal length of the telescope, the magnification being used, and seeing conditions.

#23A Light Red 25% T

• Moon - Improves lunar features.
• Jupiter - Useful for studying bluer clouds.
• Mercury - Improves observation at twilight, when the planet is near the horizon. During daylight, it reduces the brightness of the blue sky to enhance surface features.
• Saturn - Useful for studying bluer clouds.
• Venus - Use during daylight observing to reduce brightness of blue sky. Occasionally deformations of the terminator are visible.
• Mars - 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.
• Comets - Improves definition of comet dust tails.

#38A Blue 17% T

• Moon - Enhances lunar detail.
• Jupiter - Enhances 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 - Improves observation of dusky surface markings at twilight, when the planet is near the horizon.
• Saturn - Enhances low-contrast features between the belts and zones.
• Venus - Useful for increased contrast of dark shadings in upper Venusian clouds.
• Comets - Brings out the best definition in comet gas tails.

#58 Green 24% T

• Moon - Enhances lunar features.
• Jupiter - Increases visibility of the Great Red Spot. Useful for observing the low-contrast hues of blue and red that exist in the Jovian atmosphere.
• Mars - Excellent for increased contrast of Martian polar caps, low clouds and yellowish dust storms.
• Venus - Useful for Venusian cloud pattern studies. Reduces brightness of blue sky during daylight observing.
• Saturn - Enhances white features in the Saturnian atmosphere.
• Comets - Useful for observing brighter comets.

#96ND 50% T – Density 0.3

• 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
• Stars - Helpful in splitting binary stars, because it reduces glare and diffraction effects around the brighter star of the binary pair.

Product Description

This product has been discontinued from Celestron and is no longer available. Celestron color filters are mounted in black anodized aluminum cells with the Kodak Wratten Series Number individually engraved, and come available in 4 assorted kits packed in plastic cases. The cells of each filter are double-threaded, so they can be stacked (piggybacked) in various combinations. This allows you to create different color combinations and transmission characteristics, or to have the same color characteristic, but with a lower transmission. When stacking color filters, the effective transmission of the combination you create is equal to the product of the spectral transmission of each of the filters used.

Eyepiece filters are an invaluable aid in lunar and planetary observing. They reduce glare and light scattering, increase contrast through selective filtration, increase definition and resolution, reduce irradiation and lessen eye fatigue. Celestron's filters are made of high quality, solid plane parallel glass with excellent homogeneity. They're anti-reflection coated to prevent glaring and ghosting. All eyepiece filters are threaded to fit Celestron's, and most other manufacturer's, 1.25" eyepieces, and offer a full 26mm clear aperture. Kit includes: #23A, #38A, #58, Neutral Density 50% transmission filters.