In this article we are going to look at what are the best binoculars for astronomy beginners. Binoculars range in all shapes, sizes and cost. The more important question to be asking yourself is, what should you be looking for in your first pair of “binos” for astronomy viewing.
Rather than focus on what are the best binoculars for astronomy beginners, let’s discuss first how to choose the right binoculars for you. There is a bit of a learning curve when first getting into astronomy and choosing binoculars. Part of this learning curve involves discussing:
- Binocular Weight
- Exit Pupil
- Field of View
If these terms are foreign to you, don’t worry, we will cover each one of these in detail. This is because, when choosing your first pair of binoculars for astronomical viewing, you want to be sure that you understand the importance of each one of these items.
If you’re contemplating getting into amateur astronomy, then I highly recommend starting out with a good pair of binoculars before purchasing a telescope. Heck, if you have a pair lying around the house chances are they will be sufficient to get you started.
The reason I recommend starting with a good pair of binos is because:
- They’re fairly inexpensive when compared to a telescope.
- Binoculars allow you to use two eyes instead of one, which may be more comfortable when first traversing the night sky.
- Even when you decide to buy a telescope, it is always a good idea to bring a pair binos along with you.
- Often your binos can be used for terrestrial objects as well.
Okay, I think I’ve convinced you…continue reading so you can make an informed decision before deciding to purchase your first pair of binoculars.
What Can You Expect To See?
Before diving into some of the technical details around how to choose the best binoculars for astronomy beginners, let’s first discuss what you’re likely to see.
Under dark, moonless skies, even small “bird-watcher” binoculars will reveal more than 100,000 stars, compared to about 4,000 to the unaided eye. The “foggy” Milk Way that you typically see when you just look up, will reveal itself as countless thousands of stars.
Some other celestial object that are a definite must for a good pair of binoculars:
- When Jupiter is visible, two to four of its large moons can be seen.
- The planets Uranus and Neptune.
- Star clusters such as Pleiades and Hyades.
- The Andromeda Galaxy.
- And of course, the Moon.
This is just to name a few, but there are many, many other targets available that a good pair of binoculars will reveal.
Understanding the Classifications of Binoculars
Like I said previously, the learning curve is a bit steep initially but not difficult. The first thing you will encounter when reviewing binoculars is a pair of number separated by an “x”. For example, you will see binoculars listed as, 7×50, 10×50, 12×60 and the list goes on.
Let’s first break this number down so you understand completely what these numbers mean. The first number, say 10x, is the magnification factor or power factor. This means that objects will appear 10 times closer than they normally would with the unaided eye.
The next number is the objective or lens diameter. This number is express in millimeters, therefore a pair of 10×50’s has 10x magnification with an objective lens diameter of 50mm. Generally, the larger the objective lens, the more light you’ll be able to pull into the eyepiece. A desirable quality when viewing pitch black conditions.
That said, there is a trade-off with having those larger objective lenses, and that trade-off is the weight! For tripod mounting this is not such a big deal, in fact if you go above 60mm, I definitely recommend that you use one. If not, you will have difficulty stabilizing the image in the eyepiece which will make viewing objects a challenge.
Why Weight is Important
The weight of the binoculars you choose are going to play a big factor in your decision making process. Generally, the smaller the binoculars the less they are going to weight. However, the smaller you go, the less you will see when viewing celestial objects.
Therefore, you want to choose a pair of binoculars that will give you the best of both “worlds”. The sweet spot if you will. In my opinion, that “sweet spot” is somewhere around 10×50. Two very good binoculars in and around this size are the:
Both of these binoculars offer an excellent compromise between all-around quality and cost. I did an article that reviewed some of the best binoculars for astronomy beginners here at, Best Binoculars For Astronomy Under $500. You can check out that full article and my top picks after you’re done here!
The reason weight is such a critical factor is because when viewing celestial objects you will be holding the binoculars for long periods of time above the horizontal plane. This puts more strain on your arms than if you were viewing something straight out or below the plan.
For this reason I don’t recommend you stray too far from that 10×50 sweet spot unless you intend to bring a tripod along with you. If you do intend to tripod mount your binoculars from time-to-time, then be sure to pick up a tripod adapter such as the Celestron Binocular Tripod Adapter on Amazon. They are fairly inexpensive and will give you the option to use a tripod with your binoculars if you choose.
Let’s Talk Prisms…
There are two basic types of prism binoculars you will see on the market:
Roof prism binoculars have straight tubes, and are generally smaller and more expensive than porro prism binoculars when comparing apples-to-apples in optical size. Porro prism binoculars have an N-shaped light path design, and are available in a multitude of sizes.
For astronomy, we’ve found that only the very best or premium roof prism binoculars perform well under low-light conditions. For this reason, I recommend going with a good pair of porro prism binoculars. They are cheaper and offer good performance under dark sky conditions.
What is Meant by the term “Exit Pupil”
You will here this term used in many references you are likely to read…Exit Pupil. Let’s spend a moment to tackle what this concept is and why it is important.
For maximum efficiency, especially for astronomy, the light cone exiting the binoculars (or telescope for that matter) eyepiece – known as exit pupil – should be the same size as the dilated pupil of the eye. The basis of this theory is this, all light should enter the pupil rather than falling off underutilized to the surrounded iris.
So your probably wondering…”how the heck do I measure my pupil”! No need to go that far. Most people under the age of 30 have a pupil dilation of 7 to 8 millimeters under dark skies. After 30 the pupil tends to degenerate and looses approximately 1 millimeter every 20 years or so.
The general consensus in astronomy circles is to look for binoculars with an exit pupil in the 2.5mm-to-7mm range. To calculate this simply divide the objective lens diameter by the magnification.
For example, the Nikon 7581 MONARCH 5 8×56 Binocular have 8x magnification and a 56mm objective lens. Then, 56 / 8 = 7mm, within the acceptable range.
Understanding a Binoculars “Field Of View”
Another term you will hear often is field-of-view (FOV). This is the diameter of the circle you can see when looking through your binoculars. This is often expressed as the number of feet that span the field when viewed from a distance of a 1,000 yards.
More recently, you’ll hear this expressed in an angular diameter in degrees. For example, 1 degree is equivalent to 52.5 feet at 1,000 yards. As a benchmark, 10×50 binoculars typically have an FOV of six-degree-fields. As you move into larger or wide-angle lenses, the FOV can span anywhere from 8-to-12-degree fields of view
The obvious advantage of a larger field is you can see a larger portion of the sky. The main disadvantage of the larger fields is the distortion that inherently plagues these lenses. As with most things in life, there is always a trade-off!
What Makes a Good Binocular??? Craftsmanship
Once you hold a pair of good quality binoculars in your hand you will be able to feel the difference! It is important to test all moving parts. This includes the eyepiece (diopter) adjuster and the main focus adjuster.
Most binoculars are brought into focus by adjusting both the middle focus adjuster and the right eyepiece. You want to make sure that both these adjusters are able to move smoothly while apply good even pressure. What you don’t want to see is any “backlash” in these adjustments, meaning, there is some subtle movement without any actual change in focus.
It’s important to know the difference between these two adjustments – so let’s discuss them here!
The knurled knob at the top of you binoculars is the main focal adjustment. This will focus both eyepieces by the same amount. The problem with this is that most people will have one eye that is stronger than the other. This is where the diopter or eyepiece adjustment comes in.
The diopter adjustment, as mentioned, is typically found on the right eyepiece itself. Here is the process for focusing your binoculars:
- With you right eye closed, use the main (center) focus wheel to adjust the image in your left eye.
- Then focus with your right eye (left eye closed) using only the right eyepiece diopter focus wheel.
- Once your right eye diopter is in focus, remember this setting (especially if someone else will likely be using your binos) and “lock it down”.
- Now you can focus on objects by simply moving the center main focus adjustment.
Understanding Optics and Coatings
The optics and lens coating are another extremely important aspect of your binocular purchase. What separates the quality of the optics is how the binoculars will focus over the entire field of view (FOV).
While the cheaper binoculars will yield a crisp sharp image in the center of its FOV, the sharpness will degrade as you move further away from center. Generally, if the image looses its “crispness” less than 50% of the way from the center region, they are not ideal for stargazing, or anything else for that matter!
A quick check to test this 50% limit is to use your them in the daytime and focus on a distant tree. Focus on something with varying contrasts and the imperfections in the optics will be revealed.
Now a quick word about coatings. I don’t want to get too far into the technical details of this, however, you should be looking for binoculars with a multi-coat design. Most binoculars upward of $200 will be of this type, however, this will be clearly stated.
Lens coatings will optimize the light transmission and reduce flare and ghosting. While the light transmission increase is modest (approximately 93% with no coating to 97%-99% with coating), the subtle 4%-6% boost you will get will make a huge difference in the quality of the image you will pull into your eye.
The Celestron 12×50 Granite Binocular is an excellent example of a premium multi-coat design with superior optics. Although they will set you back a few dollars, at around the $400 price point they will certainly not disappoint. A perfect set of binoculars for astronomy beginners!
How Big Can You Go???
Okay, so you want one of those jumbo pair of binos you see in the magazines…no problem, let’s talk about them! Sizes of these giants used in amateur astronomy typically range from 9×63, 10×70, 15×70, 11×80, 15×80, 20×80, 14×100 and 25×100.
The price you will pay for these have an equal range from as low as $100 (I don’t recommend) to upward of $1000 dollars. This is going to depend a lot on the quality of the optics in the binos. For under $350 you can get your hands on one of the monsters, such as the Celestron SkyMaster 25X100 ASTRO Binoculars on Amazon.
For a reasonably good compromise between big size and portability you could also look at the Nikon Monarch 5 20×56 ED Complete Kit. It’s a great choice if you want to step up in size. This combo kit comes with everything you will need to get up and running with a great pair of binos. You can check it out on Amazon by clicking the image below!
The incredibly steady views that you will get from a pair of large binoculars affixed to a tripod is truly breath-taking. However, when you get into these larger sizes, the steady-viewing option using your hands is essentially lost. So please consider this before jumping into these big guys!
Follow these key factors before you consider buying your next set of binoculars:
- Generally, larger objective (main) lenses mean brighter images.
- Larger objectives lenses means heavier binoculars. Consider a tripod when going above 56mm.
- Binoculars with 7mm exit pupil lengths are a good all-around match for most users of any age. Look for binos with an exit pupil in and around this number.
- High magnification will allow you to see more objects. However, this will require better quality optics and will be more susceptible to binocular shake if hand-held.
I hope you found this article useful and be sure to check out my other articles:
- Astronomy Telescope Types
- Does The Sun Rotate?
- Does Saturn Have Clouds?
- How Far is Mars from Earth? Facts About Mars
- How To Find The North Star?
- What Is The Dark Side Of The Moon?
- Top 10 Small Telescope and Binocular Objects
- Best Kids Telescope for Viewing Planets
- What Causes the Northern Lights?
- 10 Tips For Buying Your First Telescope
- Best Binoculars For Astronomy Beginners
- Best Binoculars For Astronomy Under $500