Binoculars for Astronomy and Stargazing: Part 3

Now that we've discussed the advantages of using binoculars for stargazing, as well as an in-depth discussion about night sky targets, in Part 1, and then discussed characteristics of binoculars in Part 2, it is time to finish this three-part series by discussing what pair of binoculars you may want to outfit yourself with for soaking up the beauty of the heavens—and, it might be that a pair of binoculars you already own fits the bill!

Price and Budget

In the world of optics, be it telescopes, spotting scopes, monoculars, or binoculars, the cost of the highest-priced optics is exponentially more than the least expensive—all while looking like nearly identical products. A fair question is: Where do I enter the market?

Sound advice is to buy the best pair of binoculars you can afford. Entering the market with a low-cost pair of binos can run the risk of keeping you from enjoying the night sky right off the bat. You might take the financial loss of a cheap pair of binos and never look skyward again. Or you’ll get a taste of how much fun stargazing is and immediately want to up your optics game—at an additional cost.

There is a marked difference in performance between a $20 pair of binoculars and a $200 pair. However, the difference between a $200 pair and a $2,000 pair is not as apparent to most viewers. In general, if just starting out, you will likely be happy with a mid-priced pair of binoculars—I know I have been.

What Size Astronomy Binocular is Best for You?

As you may have digested in Part 1 and Part 2, there is no one-size-fits-all astronomy binocular. Decisions must be made regarding magnification and objective size—decisions based on what kind of night sky objects you want to view and how complex of a system you wish to employ in the field or in your backyard.

Let’s dive into some of the more popular binocular options for stargazing. The e-commerce search links below point you in the direction of binoculars of certain magnifications and sizes. You can add more purchasing options to your search by using the refinements to include “outlier” pairs that have slightly different magnifications and sizes. Example: When searching for 8x binoculars you can also expand the search to include 8.5x pairs.

7x50 Binoculars—The Classic Choice

For serious stargazing, a wonderfully wide field of view, and the option of handholding the binoculars, a 7x50 binocular is a great night sky exploration tool as the 7x50 size is and was traditionally a favorite among avid stargazers. Not only that, but a 7x50 binocular is perfect for boating and pretty good for birding as well—versatility that can add value to your investment.

• Handheld

• Almost always Porro prism

• Great light gathering

• Good for stargazing

• Wide field of view

• Also good for marine use and general viewing

If you are overwhelmed by the number of binocular options out there (there are too many!), 7x50 binoculars are a great and safe place to start (and finish) your stargazing binocular purchase journey.

10x50 Binoculars—The New Favorite

A bit more magnification can be had with a 10x50 binocular—preferred by many stargazing experts since some have noted that the 7x50 seems to be falling out of favor with manufacturers—there are fewer 7x50 options on the market now than just a few years ago (it’s a good thing I own three!). Handholding is still possible, the optic is still portable, and the 10x magnification gets you a bit closer to the stars—a 500mm lens versus a 350mm lens in camera-speak.

• Handheld (with steady hands)

• Porro and roof prism

• Great light gathering

• Good for stargazing

• More magnification than the 7x

8x42 and 10x42 Binoculars—Classic Birding Optics

If you already own a trusty (and good) pair of 8x42 or 10x42 “birding” or general-use binoculars—or if you were on the fence about getting some birding binoculars—you can easily take them into the night to view the moon, see Jupiter’s four largest moons, or take in some distant stars that your eyes have never seen before.

• Handheld

• Versatile; great for birding, travel (not too big, but not compact either), and general use

• Usually roof prism

• Good light gathering

• Good for stargazing, moon, large planets

8x56 Binoculars—More Light, Less Shake

An intriguing alternative to the 7x50 and 10x50 binocular is those that measure at or around 8x56. These give you the more manageable 8x power with big objectives and, for roof prism fans, most models at this size are in that configuration.

• Handheld. But, getting heavier… and larger

• Versatile; good for low-light birding and nature viewing

• Usually roof prism

• Very good light gathering; more light than 50mm

• Good for stargazing

• Slightly more magnification than 7x

10x70 Binoculars—A Step Up

10x70 binoculars give you the moderate 10x magnification with very large 70mm objectives for serious light gathering. When compared to their 10x50 counterparts, these optics will be larger and heavier.

• Tripod wanted due to the weight and size—not necessarily due to magnification

• Porro prism

• Great light gathering

• Good for stargazing

16x70 and 18x70 Binoculars—Serious Astronomy

Combining large objective lenses and long-range magnification, binoculars of this 16x70 and 18x70 size are usually purpose-built for viewing the night sky.

• Tripod or support needed

• Porro prism

• Great light gathering

• Good for many celestial targets

Large & Giant “Big Eyes” Binoculars

In the Navy, we called the huge binoculars on the flying bridge of ships “Big Eyes.” Some binoculars have magnification registering 20x and even 25x (1000mm or 1250mm camera lens). This magnification is what you will find at the low end of many spotting scopes. Their objective lenses range from 50mm to 150mm and all of that glass is heavy—some of these optics weigh almost 50 lb!

• Tripod or support needed

• Porro prism

• Big and heavy. Limited versatility

• Good to great light gathering

• Good for many celestial targets

Image Stabilized

For viewing those distant celestial objects without a stable support, an image stabilized binocular is perfect for bridging some deeper sky viewing without the extra gear. Remember that large objective lenses are still needed for light gathering—look for 40mm or larger objectives. The amount of stabilization does not matter if only the brightest stars and planets are visible in the optics.

• Handheld viewing at high magnifications

• Good light gathering from larger pairs

• Batteries required

Binoculars to Avoid if You Want to See Stars

• Small objective lens (20-35mm) compact travel binoculars probably won’t serve you well for anything past lunar observing. While there are some incredible 8x30 and 8x32 binoculars on the market, they simply don’t have the needed light-gathering performance for celestial targets. The top models will work in a pinch, but there are better options.

• Opera glasses are for viewing the stars on the stage, not in the night sky.

• Variable magnification “zoom” binoculars have never been top optical performers.

To return to Parts 1 and 2 of our stargazing binocular series, click here. Do you have any questions about astronomical binoculars or optics in general or thoughts to share? Please let us know in the Comments section, below!