Astro-Tech #29 Dark red 1.25" color filter

Recommended applications for this filter:
Moon - Somewhat useful for improving contrast between lunar features in scopes 10" and larger. Mercury - Improves observations at twilight, when the planet is near the horizon. Reduces brightness of terrestrial sky to enhance daylight observing. Venus - Reduces brightness of terrestrial sky in daylight observing, allowing occasional terminator deformations to be seen. Mars - Very useful for Increasing the contrast and definition of polar caps, frost areas, and maria against the ochre deserts with scopes 8" and larger, particularly when Mars is close to Earth's horizon, as the red light it passes is the least refracted by air currents in our atmosphere. Sharpens the boundaries of yellow dust clouds. Jupiter - Very useful in defining blue-tinted cloud formations against lighter-toned atmospheric features. Saturn - Very useful in defining blue-tinted cloud formations and polar regions against the lighter-toned planetary disc. Comets - Enhances the definition of comet dust tails in 12" and larger scopes.
6% transmission