Filter SW 21 red 1.25"

#21 Orange Filter

The #21 Orange Filter improves contrast when observing the Moon and planets, helping reveal subtle surface features and atmospheric details. It is recommended for telescopes with apertures of 6 inches and larger.

Recommended Applications

• Moon: Improves contrast between lunar surface features in telescopes with apertures of 6 inches and larger. It can be used with or without a polarizing filter.
• Mercury: Darkens the daytime sky to help reveal subtle differences in surface albedo that are otherwise difficult to detect.
• Venus: Darkens the daytime sky, making the planet's phases easier to distinguish.
• Mars: Increases the contrast of polar caps, frosted regions, low clouds and dust storms against ochre-coloured desert areas. It also sharpens the edges of yellow dust clouds.
• Jupiter: Enhances the structure of atmospheric bands and reveals belts and details in the polar regions.
• Saturn: Improves the visibility of atmospheric bands and emphasizes bluish tones in the polar regions.
• Comets: In telescopes with apertures of 10 inches and larger, the filter can be combined with a #38A filter to improve the contrast of orange sodium D-lines in cometary gas tails. It also improves the resolution of the coma and dust tails.
• Sun: Helps provide more accurate colour rendition when used with a Mylar solar filter. Solar observation requires a suitable certified solar filter; the orange filter alone does not provide eye protection.

Specifications