Binoculars 20×80
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 ZHUMELL20x80mm32 GIANT ASTRONOMICAL BINOCULARS  US $139.00
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 Celestron 71018 SkyMaster 20x80 Binoculars US $109.00
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 Celestron SkyMaster 20x80 Binoculars Retails for $175 US $75.00
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 Package Gemini 10x50 LW Binocular Series 1000 Monopod US $134.95
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 Celestron Photo Video Tripod US $34.99
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 Humvee 20x80 Jumbo Binoculars US $119.95
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 Garrett® Gemini 10x50 LW Binocular 10x 50mm US $74.95
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 Barska 20x80mm WP Cosmos Binoculars AB10860 US $199.94
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 33 100X100 Spotting Scope Astronomy Security Zoom Large Spy SWAT Tactical Force US $274.65
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 Celestron Photographic and Video Tripod 93606 US $26.99
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 Celestron SkyMaster 20x80 Binocular US $149.99
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Barska X-Trail 20 x 80 Binocular with Braced-in Tripod Adapter
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Zhumell 20x80 SuperGiant Binoculars
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Celestron SkyMaster 20x80 Binoculars
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Bushnell PowerView 20x50 Super High-Powered Surveillance Binoculars
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Celestron SkyMaster Giant 15x70 Binoculars with Tripod Adapter
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Astronomy binoculars?
Has anyone ever heard of these binoculars
The skymaster 20x80
The skymaster 25x100
What are these binoculars designed for, and are they good for astronomy.
As I explained in another question very similar to this, the most important property to know when considering binoculars for astronomical use is the size of the exit pupil.
If you hold a pair of binoculars a few inches away from your eyes, with the eyepieces facing you, you will see a bright circle of light in the centre of the lenses. This is the exit pupil.
Now when your eyes are fully dark adapted the pupils of your eyes are between 5 and 7mm across. The diameter of the exit pupils of the binoculars should match that of your pupils as near as possible.
To determine the exit pupil diameter of a given pair of binoculars, simple divide their aperture (eg 80mm) by their magnification (eg 20x). For a pair of 20x80s then this gives 80/20 = 4mm.
So at 4mm the exit pupil of your 20x80 binoculars will be slightly less than the size of your pupils which means images will tend to be rather dim and lack contrast. They will also be rather heavy and so a tripod would be recommended.
The 25x100s will also give a 4mm exit pupil and so they will also tend to lack contrast even though the primary lenses are bigger.
I used to have a pair of 11x80s which were excellent, while I currently use a pair of 20x100s and 15x70s.
My own receommendation would be to contact Telescopehouse which have a broad range of binoculars of various sizes. Their 15x70s are about £40 and provide a good balance between performance and price. I have a pair myself.
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Tags: astronomy, binoculars, binoculars 20x80, binoculars 20x80 bushnell, binoculars 20x80 price, binoculars 20x80 review, binoculars 20x80 zhumell, onlywire, optics, scope