- 4 Filters in protective, plastic case
- Filters double threaded for stacking
- #21 (Orange), #80A (Light Blue), and #15 (Deep Yellow)
- Neutral Density Filter (25% Transmission and o.6 Density)
Celestron lunar and planetary filters are mounted in black anodized aluminum cells with the Kodak Wratten Series Number individually engraved, and come packed in protective, plastic cases.The #21 Orange Filter blocks transmission of blue and green wavelengths. It is ideal for bringing out more detail of the belts and polar regions of both Saturn and Jupiter (including the Red Spot of Jupiter), or increasing the contrast of the edges of the plains (maria) of Mars. The #80 Light Blue Filter is used to better observe cloud patterns on Jupiter and Venus, or the polar caps of Mars and Saturn. The #15 Deep Yellow Filter is ideal for looking at many features of Mars (clouds, polar caps, or plains, as well as the belts of Jupiter and Saturn. The Neutral Density Filter, 25% transmission and o.6 density, cut down the glare, without losing any colours of the spectrum. Neutral Density Filters are great for observing the Moon, planets, or bright stars. The most important thing about filters is to experiment! In addition to the planets, make sure to use them all when observing the Moon, comets, and stars.
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 results in lower light transmission.
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.