Guide to the Best Binoculars for Astronomy and Skywatching

Stargazing is fun in a field, with a blanket, under the sky full of stars. It’s a romantic setting, but what makes it even more interesting is when you have a binocular with you. A telescope may give an up-close view of the stars, but if you want a magnification tool that you can use for other purposes as well, then a binocular is a better choice.

Astronomy binoculars are a reliable alternative to telescopes. They serve the same purpose, but with the unique viewing experience. There are many great binoculars in the market, but standard equipment designed for wildlife just won’t do. You need one that adequately collects light and provides optimal levels of magnification.

Why use Binoculars for Astronomy and Skywatching?

Many seasoned stargazers today have a pair of binoculars at their disposal to accompany their primary viewing equipment, usually a telescope. But why? Even the best binoculars on the market can’t give as much viewing power as large telescopes.

But binoculars offer one thing that telescopes cannot: portability. Binoculars are significantly smaller than telescopes, and most can be even flung around the neck with a strap. You can easily take binoculars for an impromptu trip, while a telescope can be hard to bring anywhere since you need to pack up a large piece of gear and take time to set it up.

Beyond the portability and convenience, binoculars also give a more natural viewing experience. The field of view is narrow, and you only get to use one pupil to see the image. Meanwhile, binoculars offer a wider field of view. It collects more light due to the two optical barrels. Plus, you will be using both of your eyes.

Where to Buy
Celestron SkyMaster Giant 15x70 Binocular
Oberwerk 8x42 Sport ED Binocular
SkyGenius 10x50 Binoculars
Celestron Cometron 7x50 Binocular

Factors to Consider when Looking for a Pair of Astronomy Binoculars

When you want to view stars and other astronomical bodies better, get yourself a pair of high-quality binoculars.

Magnifying power

The magnification power of a binocular is the first thing you must look for when you’re shopping for binoculars. You’ll be using the binoculars for magnification, after all.

The magnification power is represented in the first number of binocular specifications. Meanwhile, the second number is the metric diameter of the big round glass lens at the front. So, for a 10×50 binocular, it has ten times magnification and an objective lens that measures 50 mm across.

Some skywatchers prefer a high magnification to resolve thousands of light-points within dense star clusters and to pick up finer structures within galaxies. But others prefer a wide-field, space-walking experience.

But having a higher magnifying power isn’t always going to make a huge difference. Most people will do just fine with a binocular with 10x magnification since this is more than enough to look at the moon and see star clusters up close. Lower magnification is going to provide you with a wide field of view that you can appreciate.

You can go higher if you’re aiming to look at long-distance objects, and if you’re taking astronomy pretty seriously. With a 20x magnification, you can view the rings of Jupiter or see the Orion nebula.

Size of objective lenses and aperture

Like in cameras and telescopes, the aperture of a pair of binoculars affects how much light is coming in. A larger aperture means that you’re getting a bright image with a lot of detail and contrast.

The same thing goes for the size of objective lenses. Larger lenses make it possible for light to flood the optical cones to result in better image quality. For a 10×50 binocular, the number 50 indicates that the objective lenses are 50 mm in diameter.

Type of prism

Binoculars are small because they use prisms. Prisms are glass components that manipulate the light that enters the lenses. It can increase the light between the lenses and the eyepiece, increasing magnification without changing the size of the optical tube.

Two different kinds of prisms will work well for astronomy: roof prism and Porro prism. Porro prisms are more accessible and known for producing sharp images with better contrast. It concentrates light strategically to ensure that you’re getting a visible, bright image. Roof prisms are used for high-end binoculars because it allows the gear to be smaller and more protected from the elements. While they’re not as effective as Porro prisms at concentrating light, modern roof prisms can minimize light loss to create a brighter image than before.

Exit pupil

Exit pupils are small disks where images form. While the aperture and size of the lens affect how much light will be coming in, the exit pupil affects the light coming out. It must be between 5mm and 9 mm in diameter – the same size as the human pupil in low-light conditions. If the exit pupil is smaller, then it can result in a darker image.

Remember that eyes change with age. A middle-aged person’s pupil can open to a diameter of about 5 mm, while a child’s pupil can open much wider.

Eye relief

If you’re an eyeglass wearer, you have to keep an eye on eye relief. It’s the distance between the focused image and the final lens of the binocular eyepiece. As an eyeglass wearer can’t really get closer to the lens, they need binoculars with long eye relief. However, adjustable eyecups also work as well.

Focus and eyepiece adjustment

Some people find a hard time getting everything in focus. To make things simpler, get binocular with a simple focusing system. Most have a central focus knob that controls both eyepieces. Some have a diopter knob to make up for differences between the eyes. If you want a user-friendly binocular, go for one with a built-in stabilizer.

Build quality

Make sure you get a quality binocular with a quality build. Since binoculars are supposed to be used outdoors, make sure you find a gear that’s built with tough materials. It’s also great to find equipment that’s waterproof, shockproof, and dustproof.

Best Binoculars for Astronomy and Skywatching

Here are some of the best binoculars you can find for your sky watching needs:

  1. Celestron SkyMaster Giant 15×70 Binocular
    The Celestron SkyMaster Giant 15×70 Binocular is one of the best for celestial and terrestrial object viewing – not just for stargazing, but also for bird watching, driving, and other activities. Images appear crisp and clear through these binoculars. It comes with a massive 70 mm objective lenses that ample direct light to the eyes when used in low-light settings. It’s also equipped with multi-coated optics with BaK-4 prisms, bringing you sharp images.These binoculars bring a large field of view of 231 ft per 1,000 yards. As such, you can enjoy the vastness of the night sky and watch fast-moving objects. To ensure durability, these binoculars come with a rugged housing and non-slip grip. It’s also water-resistant.If you like to use a tripod with binoculars, you can buy the SkyMaster Giant with a tripod adapter.
  2. Oberwerk 8×42 Sport ED Binocular
    If you need an all-around binocular, the Oberwerk 8×42 Sport ED Binocular is a great choice. It’s tough, compact, and comfortable to use. It can create clear and colorful images during the day and bright and sharp stars at night.Its extra-low dispersion ED glass brings richly colored images. It comes with an 8.1-degree field of view perfect for spotting interesting things in the night sky.It’s a grab-and-go set of binoculars that you can bring to your impromptu viewing trips. It’s also waterproof.
  3. SkyGenius 10×50 Binoculars
    The SkyGenius 10×50 Binoculars for Adults is a versatile and powerful magnifier, perfect for stargazing, bird watching, hunting, and watching sports events. The specs of the lenses are just right yet powerful.The lenses have an aspherical design and a multi-layer corrective optical coating. It can give a field of view of 367 ft per 1,000 yards. Because of these, the binoculars create HD light transmission and improved image brightness.If you’re an eyeglass wearer, you can still use the binoculars, since they have rubber-covered eyecups you can twist up or down to meet your comfort level. It’s built with a durable structure and rubber armor to guarantee no-slip grips.
  4. Celestron Cometron 7×50 Binocular
    For beginners and young astronomers, the Celestron Cometron 7×50 Binocular is the perfect grab n’ go binocular. It’s an entry-level gear that has impressive light-gathering capabilities. It may be cheaper than most great binoculars, but it’s one of the best in its category.This set of binoculars features a BK-7 prism, which provides a clearer image due to perfect collimation alignment. It brings a wide field of view at 357 ft. per 1,000 yards, so viewing the vastness of the night sky, a fast-moving sports event, and the flying birds is never a problem. It also gives a 13 mm eye relief, making it comfortable to use for eyeglass wearers.The casing of this binocular is made from rugged aluminum material, paired with water-resistant, non-slip body armor.