Agena 2" Color / Planetary Filter - #47 Violet

Color filters can be very useful for enhancing your views of the Moon and the planets. Depending on the atmospheric conditions, the telescope being used, the observer's experience, and the planet being observed or photographed, the advantages of color filters can be anywhere from subtle to dramatic. The right filter can make all the difference between seeing several small craters in the floor of Clavius on the Moon or not; seeing five or six swirls in Jupiter's belts or not; or seeing the inner Crepe Ring of Saturn or not.

Agena's 2" color/planetary filters are manufactured from the purest optical glass and are dyed-in-the-mass (not simply "color coated") for premium performance. They thread into the barrels of virtually any 2" telescope eyepiece. Each filter cell has a male and female 2" filter thread (M48x0.75) on opposite sides, so multiple filters can be stacked to achieve selective filtration of the visual color spectrum. The clear aperture is 43mm and each filter comes in a protective plastic storage case.

The #47 Violet Filter stops red, yellow, and green colors. It is useful for detecting high clouds and haze in the Martian polar cap regions and during the violet clearing. It is most useful in observing Venus because of its ability to reveal dark shading in the upper atmosphere. It also helps to view the ring-structure of Saturn. The filter is great for enhancing lunar detail too. Its low transmittance makes it suitable only for larger telescopes above 8" of aperture.