Best Astronomy Binoculars 2020

When it comes to stargazing and exploring the cosmos through a lens most people would probably call to mind the image of an astronomer’s telescope. These have their obvious benefits and we’ve outlined some of them in our post about the best telescopes for kids and starters. However, astronomy binoculars offer an affordable alternative that are not only cheaper but have the added benefit of being easily transportable and useful for day time use in all kinds of circumstances.

Some astronomers use astronomy binoculars in conjunction with their telescopes.  They scan the night sky with the binoculars to find an object then use the telescope to examine it in more detail.  These same binoculars might also be used at sporting events, concerts, or bird watching, but they need to be lightweight so that they are not cumbersome to use when swapping between telescope and binoculars.

All the below binoculars are best sellers on Amazon each with great reviews. Celestron are a brand leader in both telescopes and binoculars, as well as other optical instruments.

SaleBestseller No. 1
Celestron 71018 SkyMaster 20 x 80 Binocular
  • 20x magnification porro prism binocular
  • Giant 80 mm objective lens offers maximum image brightness in low-light and long-range conditions
  • Ultra sharp focus across the field of view
  • Large center focus knob for easy focusing
  • Multi-Coated optics for sharp, clear views
SaleBestseller No. 2
Orion 9326 Giant View 25x100 Astronomy Binoculars
  • Our biggest and brightest astro-binocular, featuring 100mm objective lenses and strong 25x magnification
  • Fully multi-coated optics, high quality BAK-4 prisms and internal baffling ensure sharp images and pleasing contrast with maximum light throughput
  • Barrels are cross-reinforced for maximum structural rigidity and unflinching optical alignment
  • Long 18mm eye relief lets eyeglass wearers see an unrestricted field of view without removing their corrective lenses
  • Weighs 10.1 lbs. - Tripod recommended for comfortable viewing (tripod sold separately)
Bestseller No. 3
ESSLNB Astronomy Binoculars 13-39X70 Zoom Binoculars for Stargazing with Phone Adapter Tripod Adapter and Case for Stargazing Terrestrial Viewing Hunting
  • Binoculars for adults with zoom 13-39X magnification optical system and wide field of view (288 ft/1000 yards) not only fits observing astronomy but also fits bird watching. Package include tripod mounting rail adapter which can help you to connect with tripod so that you will get a stable image and enjoy sightseeing easily rather than hold the binoculars for astronomy by yourself.
  • 70mm Large Fully Multi-coated objective lens available lead free glass and multiple layers of anti-reflective coatings ensures that the image you view will be as bright and sharp as possible, delivering 99.5% total light transmission. So this astronomy binoculars can show you a high light transmittance, clear, bright and no color difference image even in a low light environment. Good for beginner star gazers and to study the moon.
  • Astronomy Binoculars with phone adapter and Tripod Adapter: Smart phone adapter which can 180°angle and length adjustment, is easy to connect with giant astronomical binoculars and take videos or images in the distant world and share in your social media. Tripod adapter for steady, hands-free viewing.
  • Comfortable to use: Long eye relief is ideal for eyeglass wearers. ±5 Diopter adjusting range helps you better observation without wearing glasses. Eye cup keep from glare, you will get a better image. The large centre focus dial makes sharp focusing quick and easy.
  • Easy to carry: Comes with A big carrying bag, this zoom binoculars is convenient to store and portable. Cleaning cloth helps you maintain. A neck strap can help you free your hands.

Astronomy Binoculars Buyer’s Guide

It’s worth paying a little more for your astronomy binoculars because of the differences between the cheaper models that deliver views with blurry edges and the clearer, more accurate binoculars that minimise this image distortion.  The better binoculars are those with lenses created with extra low dispersion (ED) glass. This type of glass is used in all kinds of optical instruments due to its ability to produce clearer images.  

Prism Types

As well as the glass there is the prism type to consider.  The consensus among stargazers is to choose astronomy binoculars containing a porros prism type as this kind of prism delivers more light from fainter celestial objects.  For all other daylight use the roofer type prism is the norm as it is smaller and therefore allows for smaller and lighter binoculars.

Build Quality

Another factor to think about is the built quality of the binoculars. They are likely to be exposed to cold, moist air during the winter months.  There is also a risk that they may be dropped or knocked during fieldwork, and we must also consider that since they are handheld devices pressed against the eyes, the look and feel of the materials used is a factor.


Magnification is another variable, but generally speaking the greater the magnification, the heavier the binoculars, so you’ll need to find a happy medium.  Heavy binoculars can soon feel like a burden for tired arms but people vary so the right pair for you may be heavier or lighter than the pair suitable for anyone else.

The higher the magnification the more apparent is the shakiness you see when viewing objects.  If your binoculars are too heavy for you and the magnification is on the high side then your view will be spoiled by the shaking.  You could mount them on a tripod to overcome this, or simply buy a lighter pair with lower magnification.

Magnification is denoted by the first of the two numbers you’ll see in all the product descriptions.  Thus 8 x 42 binoculars will magnify images to eight times what you can see with the naked eye. A magnification of up to 10 is most suitable for astronomy.

Best Astronomy Binoculars

Lens Diameter

However, the second number denotes the diameter of the binocular’s lenses, and this is actually more important than the magnification.  Lenses collect light from objects so the larger the lens, the more light they collect. The human eye’s lens diameter is about 6mm, so you can imagine how much more light a lens that 42mm can collect.

Thus 8 x 42 or 10 x 50 are suitable for low light conditions and sky watching.  They are also useful for sailing when you might be looking into the distance under cloudy skies, or at dawn and dusk.

 7 x 35 and 10 x 32 are best for daylight outdoor use (bird watching, camping etc), and 8 x 25 and 10 x 25 ten to be the lightweight set for general use at track and sporting events.

Field of View

Another point worth mentioning is the trade-off between magnification and field of view i.e. the total amount of sky you can see through the lenses.  Higher magnification binoculars obviously help you to see more detail but they show a smaller field of view. This means it’s less easy to find objects in the night sky because you’re looking at less of it and you won’t see as many reference points that help locate an object. 

It’s a bit like being too close to a location on Google Maps.  You sometimes have to zoom out to see where it is in relation to more familiar landmarks.

Exit Pupil

The exit pupil is another measurement you’ll see mentioned with regard to binocular specifications   This value is the result of dividing the lens diameter by the magnification, so a 7 x 35 pair will have an exit pupil measurement of 5mm (35 divided by 7).

Ideally this figure should be higher than 5mm.  In dim light the human eye’s pupil can widen to 7mm, so if your binoculars can improve on that, so much the better.  A 7 x 50 pair for example would give you a value of 7.14mm.

Relative brightness is a measurement related to exit pupil and is calculated by squaring the exit pupil value e.g. (7.14 x 7.14) equals 50.97.  That is more than twice the relative brightness of a pair of binoculars with an exit pupil of 5mm – (5 x 5) equals 25.

Eye Relief

Binocular eye relief is a measurement of the distance from the eyepieces to the eyes while the whole field of view is in view.  The best option is a longer eye relief.

Field of view is usually denoted in feet and as previously mentioned this decreases with increased magnification.  

Most binoculars have a central focus wheel but some may have what’s called a diopter adjustment ring on one of the barrels.  This is designed to help those who need to compensate for differences between their two eyes.


Before you buy your first or next pair of astronomy binoculars, think about how you’re likely to use them.  If you plan to have fixed in one place, perhaps even on their own tripod, then you could opt for a heavier pair.  If on the other hand you will also use them on field trips, camping, sailing, or going to any sporting events, go for the lighter pair.  Your neck and your arms will thank you for it.

Last update on 2022-07-06 / Affiliate links / Images from Amazon Product Advertising API

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