Astro Essentials 1.25'' #21 Orange Filter

Astro Essentials 1.25" #21 Orange Filter

  (2 Reviews)
✓ 2 year warranty


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About this product

Model:  ae_fltr_21_125
Part Number:  AD062

Astro Essentials 1.25" #21 Orange Filter

Astro Essential colour filters for astronomy are most often used to enhance contrast when observing the Moon and planets.

Results depend on seeing conditions, the telescope and the target being observed or photographed but the right filter can make a significant difference when, for example, viewing the lunar surface or teasing detail from Jupiter's weather bands or Saturn's rings. 

See our handy guide to colour filters and how they can help improve your lunar and planetary visual observing.

Wratten #21 Orange Filter

  • This filter really helps with enhancing lunar features.
  • The brightness of the daytime sky is reduced significantly, so is useful for observing both Mercury and Venus during the daytime, especially for revealing surface features on Mercury.
  • Used on Mars, it enhances the boundaries of dark surface features.
  • Both Jupiter and Saturn benefit by increasing the contrast between their dark belts and bright zones. Jupiter’s great red spot also pops into view using this filter.
  • Used on bright comets in larger telescopes it enhances the definition of the coma and any dust tail.


  • Wratten #21 Orange Filter
  • 1.25" Filter Size with M28.5x0.6 Threads
  • Premium optical glass with dyed-in-the-mass colour mounted in a precision metal cell
  • Threaded both sides to enable stacking
  • Supplied in a protective storage case
  • Manufactured by GSO in Taiwan

Customer reviews

Average Rating (2 Reviews):  
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Rating (max 5):  
Orange filter
05 July 2022  | 

Been using this to observe the moon. The first thing you'll notice unsurprisingly is that the moon is a deep shade of orange. This certainly helps to reduce the bright glare so no moon filter needed. The surface details seem far more pronounced. The crater shadows seem sharper. You can see a lot more smaller surface detail which tends to be a bit washed out without the filter. Overall the image just seems sharper and more detailed. A great investment for little money.

Rating (max 5):  
Orange filter
22 December 2020  | 

Purchased 4 filters plus 1 filter included for free. Loads of fun swapping them around, the orange one seems great for the moon. Well made comes in solid plastic container and cheaper than buying a set.


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