High Point #12 Yellow Filter - 2" - 12F2

This High Point 2" Colored Filter has a Wratten number of #12, which is Yellow with a transmission of 74%. A yellow filter will enhance features on the Moon and Venus, and increase the definition in comet tails. When observing Jupiter and Saturn, you can expect a yellow filter to help you see the orange and reddish features of the belts and zones better and to penetrate and darken the subtle blue tones of the atmospheric currents. Mars will also benefit from a yellow filter in several ways. It will darken the maria, canal markings and oases, and at the same time, lighten the desert regions. A yellow filter will also sharpen the boundaries of Martian dust clouds. If you have a telescope with at least 11" of aperture, you can use a yellow filter to improve detail on both Neptune and Uranus.

Colored filters can be 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.

All of High Point's colored filters are made of high quality, solid plane parallel glass that has been anti-reflection coated to prevent glare and ghosting. They have a full 43mm clear aperture, and are mounted in a black anodized aluminum cell that is threaded on both sides to fit most 2" eyepieces and stack with other 2" HPS filters.

Please note that the effectiveness of this filter depends on several factors, including the aperture and focal length of your telescope, the magnification being used, and the seeing conditions at the time. Remember that filters lower the amount of light that reaches your eye. You'll need an aperture of at least 8 inches for dark filters such as the #47 Violet, with only 3% transmission, the #25 Red with just 14% transmission, or the #38A Blue with 17% transmission.