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.
GSO's 1.25" 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 1.25" telescope eyepiece. Each filter cell has a male and female 1.25" filter thread (M28.5x0.6) on opposite sides, so multiple filters can be stacked to achieve selective filtration of the visual color spectrum. The clear aperture is 25.6mm and each filter comes in a protective plastic storage case. Made in Taiwan.
The #21 Orange Filter reduces or blocks transmission of blue and green wavelengths. It sharpens boundaries between yellow-orange areas and blue-green regions on Mars, resulting in a darkening of edge-detail in the Maria. Use it on Jupiter and Saturn to sharpen contrast and enhance detail in the belts and polar regions and to bring out the Great Red Spot. The filter also enhances viewing of festoons and polar regions. It will also slightly increase surface details on Saturn, particularly highlighting the bands and blue polar regions. This one behaves very similarly to the #15 but gives slightly more contrast
The filter greatly enhances lunar features. It can be used to reduce sky brightness during daytime observations to improve viewing of Venus and to reveal surface features on Mercury. When used on comets in large telescopes, the orange filter enhances definition of dust tails and comet-heads.
Aug 25, 2017
#21 Orange FilterPros: Cons: Comments:
Excellent. 2017 solar eclipse with this filter gave an image of sunspots/corona that was clear and detailed during the eclipse. It appeals to a larger audience as it more closely resembles what people think the sun should look like.
This review was provided courtesy of AgenaAstro.comJan 31, 2017
Another great filter from GSOPros: Cons: Comments:
GSO has done it again... this 1.25 #21 color/planetary filter works great... and at great price too! Even though I'm a beginner... I will be buying from them again... that's for sure! I'm sure that there are more expensive filters out there... but where I'm coming from... this works for me!
This review was provided courtesy of AgenaAstro.comMay 6, 2016
Amazing....just what I needed...excellent pricePros:
Lightweight,Accurate,Strong Construction,Easy to Use,Great Price,Quality LensesCons: Comments:
With this #21 orange filter I had the most amazing views of the Moon that I ever had. The field of view was very sharp from edge to edge. It was just what I needed at an excellent price. If you have a 150mm telescope I recommend to get this filter in your filter set.
This review was provided courtesy of AgenaAstro.com
Gunsmokeray New Member
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- Review by Ray of Bossier City, LA.