Using a pair of binoculars for astronomy is ideal when you first start out on your stargazing adventure. They’re smaller than telescopes, normally cheaper and much easier to use, but is there any place in serious astronomy for binoculars?
Once you have bought a decent pair of star watching binoculars, you’ll probably never want to stop using them. Like many avid astronomers, no matter how large your hoard of telescopes gets, you will always want to keep a pair of binoculars at the ready.
For the best experience, you will need to choose a pair of binoculars actually designed for astronomy. We list our picks for the best binoculars for astronomy and stargazing later, but if you want to choose for yourself, what should you be looking for?
Where To Buy
Binoculars vs Telescopes for Astronomy
You may have previously thought telescopes were the ultimate go-to device for watching the stars at night. However, binoculars can offer several distinct benefits for the amateur astronomer, beginner and intermediate alike.
Binoculars Are a More Practical Size
Perhaps the biggest advantage, excuse the pun, is the size. Even your smaller telescopes will still be significantly larger than a pair of binoculars. This can hinder the portability, and most will also need some sort of tripod — very hard to whip out of your backpack for that impromptu meteor storm.
For beginners to stargazing that size can be quite off-putting. Normally a telescope will be larger to offer greater magnification. With greater magnification, however, comes a more narrow field of view. Who wants to look at close-up darkness because you can’t find any stars?
A Wider Field of View with the Best Binoculars for Astronomy
A limited field of view can be a problem when you don’t know where the celestial objects you are trying to view are located. A wider field of vision that you get from a pair of astronomy binoculars can allow you to scan the skies while giving a better appreciation of where objects are.
With the best binoculars for astronomy, you use both your eyes at the same time which makes it easier to find your way around the stars. There’s plenty of evidence that your brain forms a better image when it receives data from both eyes rather than one. Both color perception and contrast can be improved when using binoculars rather than a telescope.
The Image is the Right Way Up With Astronomy Binoculars
Telescopes in general will show upside down images or mirror images of the night sky, making it more difficult to navigate. With the best binoculars for astronomy, everything is the right way up just like you would see with the naked eye.
Along with the larger field of vision, the more comfortable view and the corrected image, the essential skill of hopping between stars will be much easier to learn. The shallow learning curve of using binoculars makes them ideal for younger stargazers who want to discover the joys of astronomy.
Binoculars will be Much Cheaper
While there are premium binoculars, like the “giant” or image stabilization binoculars available, in general, they will be less expensive than a similar telescope. When you buy a pair of binoculars or even a monocular, you have all the equipment you need, unlike telescopes which need eyepieces, filters, and mounts, etc, etc.
The Disadvantages of Astronomy Binoculars
There are a few disadvantages to stargazing with binoculars and you may eventually want to move up to a telescope for better astronomy.
The wide field of view which binoculars offer comes at the expense of magnification. If your main goal is to study the finer details on distant planets or study the structure of faraway galaxies, binoculars just won’t offer enough magnification.
Plus, despite binoculars normally being less bulky than telescopes, some larger or “giant” astronomy binoculars will be tiring to hold for any length of time. The higher the magnification of your binoculars will often mean a much larger size.
To sum up best the differences between telescopes and astronomy binoculars we hand over to Bill Burgess. Burgess Optical is a company renowned for its custom-built telescopes and planetary eyepieces. In the following short video, he explains why a pair of good astronomy binoculars might be the best choice when starting your stargazing adventure.
Are Binoculars Good for Astronomy or Just for Beginners?
We have used terms like beginners, starting out in astronomy or new to astronomy a lot in this article so far. That doesn’t mean you are going to forget about your binoculars as you progress in your astronomy hobby.
The number of stars you can see all depends on their brightness. Obviously, you could see a 100-watt light bulb from a further distance than a 40-watt bulb. However, stars are not measured in watts, but rather magnitude.
Stars of the first magnitude are the brightest in the sky, with dimmer stars having a higher magnitude number. The naked eye can only see stars with a magnitude of six or lower, approximately 5946 stars. With just a 50-inch objective lens, binoculars enable you to see stars up to a magnitude of 10.3, which is around 409,194 stars.
Choosing the best pair of space binoculars now is an investment which could last you many years. If somebody in your family shows an interest in astronomy, binoculars are always a good Christmas gift for stargazers. Just make sure you buy a pair of binoculars designed for astronomy and not bird-watching.
What’s the Difference Between Astronomy Binoculars and Traditional Binoculars?
When searching for the best binoculars for astronomy, consider whether you are just going to use them for stargazing, or also want to use them during the day. While we said binoculars which are designed for birdwatching are not good for astronomy, there are some which can do both well.
Specialized star watching binoculars tend to focus more deeply than those designed for bird watching, ball games, rock concerts or other terrestrial viewings. A more distant point of closest focus is ideal when viewing objects millions of miles away. However, birds or head banging musicians will be much closer.
If you want to use your space binoculars in the day, look for those with an adjustable focus for closer range. A central focusing knob in the middle of the barrels can make it easier to jog the two light paths for a clearer image.
You will also want to consider a lighter pair of binoculars, with the center of the mass being comfortably over your palms. If the front lenses are too large, they will create a lever that puts pressure on your wrists. For fast moving action, you don’t want to miss things because your wrist is just too fatigued.
What to Look for in the Best Binoculars for Astronomy
Let's start by looking at some of those different numbers you’ll see, which are used to classify binoculars — what do they all mean? Armed with that knowledge we will then look at which sizes make the best binoculars for astronomy, looking at the arguments for bigger versus smaller.
If you go for bigger binoculars, you will need some sort of tripod for a steady view; alternately you could use technology, with image stabilization binoculars. Finally, we look at what anti-reflective coatings you need for the best night vision for astronomy, and features you should look for if you wear spectacles.
What Do All the Numbers Mean?
When looking for binoculars, you will have noticed they nearly always feature two numbers at the start of the description like 7 x 50, or 25 x 100, for example. You might assume that's the magnification — and you would be half right.
The first number refers to the magnification of the binoculars, so in a pair of 10 x 50 bins, there is 10 times magnification — i.e. objects will appear 10 times larger or closer than with just your naked eye.
The second figure refers to the size, in millimeters, of the lens at the front of the binoculars — the objective lens — which collects the light. Contrary to popular belief, in a good pair of astronomy binoculars, or a telescope for that matter, light collection is more important than magnification.
The size of the objective lens could also be thought of as the aperture, with 50mm being a good light gathering area for stargazing. Compare an area of 50mm to the puny 6mm size of the average human’s pupil in each eye, and you can understand why a binocular allows you to see so many stars.
Magnification Versus Objective Lens Size
Larger magnification often means a more unstable image, as every single hand movement, tremor or shake will also be magnified. To avoid any shakiness of the image, you will need to either invest in a tripod (more of that later) or choose a lower magnification.
The objective lens size is perhaps the most important feature of any binoculars used for skywatch astronomy (not to be mixed up with skywatch astrology). The larger the lens, the more light will get in and the brighter the image will appear. The best binoculars for astronomy should have at least 50mm, preferably 70mm and above, objective lenses.
How Is the Field of View Measured?
Another important measurement you should know, but one which is not featured in those two number classifications is the field of view. How much of the sky you will be able to see through the binoculars is referred to as the field of view.
A field of view is often expressed in terms of the width in feet of the image at 1000 yards. In astronomy, we are often pointing at objects which are thousands of light years away and that measurement doesn’t work as well as the angle of view.
A degree will tell you how much sky you can see in a circle with a diameter of that degree. Unless you’re a retired pirate or have recently been captain of the USS Enterprise, that probably won’t mean too much either.
A simple and practical guideline often used to explain the angle is to hold your fist clenched at arm's length. The image of your fist will be about 10 degrees wide while the full moon is approximately 0.5 degrees wide.
What Are the Best Size Binoculars for Astronomy?
You may have already decided you want the binoculars with the highest magnification or a larger objective lens for more light. However, perhaps the most important aspect for many, especially beginners, is the actual physical size of the binoculars.
As well as weighing more, larger binoculars will need some form of a tripod if you want to use them for longer periods. A tripod can hold larger binoculars steadier for the higher magnification they will have, but a normal camera tripod will only have a movement position of about 30 degrees.
Most large binoculars will come with a special mount in the middle, or you can attach one, which allows for more vertical movement. This will increase the amount of sky you can see and how effectively you can track planets or stars — it’s all getting a bit telescope-like now!
The best size binoculars for astronomy will be those which offer a compromise of performance and size. Popular sizes include 7 x 50, 10 x 50, or even 8 x 42. Any larger and you will need something to stabilize the image, any smaller and the binoculars won’t let enough light in for a good view of celestial objects.
The following YouTube video explains the different sizes of binoculars you should consider when choosing a pair for stargazing.
What About the Lenses? Should They Have Special Coatings?
As we keep saying, binoculars and telescopes are all about the light they collect, pretty much like the human eye. When light enters your binoculars, it hits many glass surfaces on the way from the objective lens to the eyepiece.
If the glass is untreated, a small amount of the light can be lost every time it hits a glass surface. This means that less light actually reaches the eyepiece and your pupil, which will result in a dimmer image and lower quality of star watching.
Manufacturers will apply anti-reflective coatings to some or all the glass surfaces, in varying degrees. You can often see the results of these coating as a colored hue, such as purple, red or green, on the lenses.
The more layers of coating applied, and the more surfaces coated will mean a brighter image and can be classified in the following 3 ways:
- Fully multi-coated means all lenses will have multiple layers of anti-reflective coatings. This is the holy grail of lenses but often quite expensive.
- Multi-coated is when only the air-facing or external lenses have been treated with several layers of coating.
- Fully coated tends to be the cheaper option with each lens having just a single coating of anti-reflective chemicals.
Can I Use Binoculars for Astronomy If I Wear Glasses?
The simple answer is yes! Those adjustable eyecups, sometimes rubber or maybe a screwing mechanism, allow you to move your eye closer to the glass eyepiece. The normal rule is that if you wear glasses you should make the eyecup as small as you can to get your eyes as close as possible.
Manufacturers will often list a specification known as eye relief, or how far in millimeters your pupil should be from the eyepiece for a full image. If binoculars list the eye relief as 15mm, this means your pupils should be as close to 15mm away from the eyepiece as possible for perfect focus.
If you do wear glasses, you should always look for binoculars which have an eye relief of more than 12mm. Less than 12mm and the gap between your glasses and the pupils of your eyes may physically prevent your eyes from getting close enough for a full view.
The Best Binoculars for Astronomy and Stargazing in 2019
With so many binoculars available, many sporting the qualities we listed above, how do you know which are the best binoculars for astronomy? Whatever you do, don’t just go to your local discount store and buy a bargain pair because they say 10 x 50 on the box.
We have looked at many of the most popular and best selling star watching binoculars to bring you, in our opinion, five of the best.
The MiniGiants from Orion telescopes falls in between the category of handheld binoculars and the “giant” class of binoculars. You will eventually need a tripod and adaptor to get the best results, which unfortunately aren’t included.
However, what makes these space binoculars worth the money is the multi-coating of all the glass surfaces with anti-reflective chemicals. The barrels are also treated internally with an anti-glare treatment.
The light transmission of these binoculars is superb, and the anti-glare internals ensures there’s less ghosting while improving the levels of contrast. The objective lens even features a funky purple hue for that extra non-reflective night vision look.
With a level of 15x magnification and 63mm of aperture in each objective lens, they provide a 3.7-degree field of view. That’s roughly enough to view all of Orion's Belt on a clear night.
A huge 19mm of eye relief makes them ideal for astronomers who wear glasses, and the excellent optics will allow you to see more than many other binoculars. For beginners, there are no reported collimation issues, causing you to see double, and very little need for adjustment.
At first glance, these giant binoculars from the Celestron Skymaster range may not seem like they should be on a best-of list. They don’t have fully multi-coated lenses, a rather average 13mm eye relief, and many reports of collimation issues.
However, they do offer 15x magnification, with generous 70mm objective lenses for a very affordable price. This perhaps explains why they are some of the most popular astronomy binoculars on the market.
The Skymaster does feature multi-coated lenses, but some internal glassworks are not coated — it shouldn’t reduce their light sensitivity too much. The eye relief of 13mm is only just suitable for glasses wearers and you may have to push these closer to your eyes than the Orion MiniGiants.
The field of view they offer is slightly larger than the Orions though, at 4.4 degrees, due to the larger objective lens. That larger lens also makes the body more “giant” and it does feature a tripod adaptor, which you will need to use for extended astronomy.
The main problem for many with these binoculars will be them coming out of collimation. When talking about binoculars, collimation is when the two eyepieces show you an almost identical view for the brain to process as a single image. Badly collimated binoculars will mean you see double, which is not great for astronomy!
Fortunately, there are some hidden adjustment screws so you can realign these Skymaster binoculars. At this price, they should be a great budget option for beginners, but many will be put off by the quality of collimation which can produce hit and miss images.
These binoculars, from Orion again, are a great mix of value and quality in a compact easy-to-use format. A large field of view, over 7 degrees, makes them perfect for those new to astronomy who don’t quite know where all the stars are yet.
These metal-bodied binoculars use two 50mm objective lenses, which are bordering on the very minimum you need for celestial viewing. The trade-off for the wider field of view is a reduced magnification of just 7x.
However, this will result in a more stable image as you sweep across the skies. It will be easier to spot those brighter galaxies or constellations, although these binoculars won’t reveal too much detail. At just 28 ounces in weight, there's very little need for a tripod, although the Scenix can accept an adapter for mounting and longer observations.
When used for lunar astronomy though, the Orion Scenix can reveal a lot of detail — a treat for people who have never looked at the moon through magnification before.
The purple hint to the objective lens is indicative of a multi-coating for anti-reflection, and the binoculars use high-quality BaK4 prisms. A large knurled center focus adjustment allows for a close focus of 14 feet, and the eye relief of 20mm is great for both glasses and non-glasses wearers.
Normally we wouldn’t recommend any binoculars with an objective lens of less than 50mm as star watching binoculars. However, these compact bins from Gorsky are inexpensive, well constructed and very popular in astronomy circles. Maybe it is the included smartphone adapter for taking photos that appeals to many.
The Gorsky HD binoculars feature fully multi-coated lenses, with a green film over the objective and blue over the eyepiece for clearer images. A durable body is armored with shock absorbing rubber for some of the toughest binoculars you can get — my six-year-old son has already dropped these six times and no broken optics, yet!
The 10x magnification offers a pretty decent 5.8-degree field of view, which can allow you to see all of Orion’s Belt and a few surrounding nebulae. Lunar views with these binoculars are both bright and clear, with a crisp level of detail.
Like the earlier featured Celestron, there have been some complaints of poor collimation with these binoculars. Unfortunately, there didn’t seem to be any user-adjustable realignment screws or control, and this could be a problem for some.
Furthermore, the eye relief of only 12mm means some users wearing glasses could struggle to see a decent image. However, they could always attach the smartphone attachment and view on the screen, or take shots of their stargazing experience.
These binoculars may take many beginner astronomers over their budget limit. However, if you struggle to keep your binoculars stable, even if you haven’t been drinking caffeine or alcohol, the extra investment may be worth it.
Along with the cost, comes the largest magnification. At 18x it’s the biggest of any of the models we've looked at in this astronomy binoculars buying guide — though only just!
Canon’s Super Spectra coating on the objective lens doesn’t just look cool but also prevents the reflection of light which can dim the image. Looking like something from a sci-fi movie, these binoculars use the same image-stabilizing tech used in Canon’s professional broadcast equipment.
All this technology comes at a cost though. The higher magnification reduces the field of view to a measly 3.7 degrees, so you get a steady image but not of too much.
Additionally, although it features a 15mm eye relief which is comfortable for glasses wearers, the exit pupil at 2.8mm is smaller than most human eye pupils.
We haven’t really mentioned exit pupil too much as it doesn’t affect most binoculars. However, you get the exit pupil size by dividing the objective lens size by the magnification. An exit pupil size or the size of an image which is smaller than your eye’s pupil will result in sub-optimal viewing.
Although we loved the idea and look of these binoculars, many would argue it’s hard to recommend such a costly pair of binoculars to a new astronomer. It may cost more than a telescope and tripod, but it’s a lot more portable if you suffer from the shakes — you want to view the stars in the sky, not some blurry, light-up tadpoles.
Are binoculars good for astronomy? Yes definitely, but don’t think of them as a substitute for a telescope. When you’re starting out, it will definitely be much easier to track the skies with both eyes and a wider field of view. It will also normally be cheaper too.
For seasoned astronomers and readers of our site, a pair of star watching binoculars is a useful tool to keep in your backpack or kit bag. They are infinitely more portable than larger telescopes and can be used for spotting unfamiliar stars and galaxies in less light polluted areas.
When starting out, you’re going to want a pair of astronomy binoculars which are easy to use but can grow with you as your astronomy hobby reaches for the stars.
The best binoculars for astronomy, in our opinion, are the Orion Mini Giant 15 x 63 Astronomy Binoculars. They tick all those boxes we want, in a pair of binoculars which are halfway between handheld and the “giant” tripod binoculars — any larger and you may as well take your telescope.