Apertura Lunar & Planetary Filter Kit #1
This Apertura Lunar and Planetary Filter Set is an affordable and useful bundle, providing a broad range of viewing capabilities. This 4-piece filter set requires telescopes with apertures of approximately 8″ or greater. Included in the filter kit is the 80A Blue, 58 Green, 25 Red, and a Neutral Density ND96-0.9 Filter in a plastic storage container.
Colored filters are an essential aid for planetary and lunar viewing. They reduce light scattering and glare while increasing contrast via selective filtration. Colored filters also provide increased definition, reduced irradiation, and lessen eye fatigue.
#80A Blue Filter – 30% Transmission – Use a blue filter to study surface features and polar ice caps on Mars, or to improve Mercury’s surface markings at twilight, when the elusive planet is low on the horizon. A blue filter is also useful for the observing the Great Red Spot on Jupiter or to enhance the boundaries between the giant planet’s reddish belts and their adjacent bright zones. When observing Saturn, a blue filter will enhance low-contrast features, such as those found in the belts and zones. Checking out a comet? Use a blue filter to bring out definition in its gaseous tail.
#58 Green Filter – 24% Transmission – A green filter will enhance views of the Great Red Spot on Jupiter, as well as lunar features on the Moon. Mars observations are enhanced pretty much across the board, including the polar ice caps, low clouds, and dust storms. With the 58 green filter, you can more easily see the cloud patterns on Venus, see white features in Saturn’s atmosphere, and observe brighter comets as well.
#25 Red Filter – 14% Transmission – When observing Jupiter and Saturn, a red filter will help you observe clouds that have a bluish hue. A red filter will darken the blue sky for beautiful daytime observations of Venus and Mercury. Mars will also benefit from a red filter in several ways. It will enhance polar ice caps as well as surface details, and will also sharpen the boundaries of yellow dust clouds.
Neutral Density ND91 Filter – 13% Transmission – A neutral density filter is great for looking at the Moon or other bright objects, such as Venus, without distorting the color. It will dim the light coming to your eye so that you can see more detail. This ND Filter, also known as a Moon Filter, has a density value of 0.89.
All Apertura 1.25” 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 26mm clear aperture and are mounted in a black anodized aluminum cell that is threaded on both sides to fit most eyepieces and stack with each other.
Please note that the effectiveness of these filters depends on several factors, including the aperture and focal length of your telescope, the magnification being used, and the seeing conditions at the time.
For scopes under 8”, we recommend filters with higher transmissions, such as those included in our Apertura Lunar & Planetary Kit #2.