EQUIPMENT

Binoculars are one of the most accessible and rewarding tools for amateur astronomers. Whether you’re just getting started or already own a telescope, a good pair of binoculars can open up a surprisingly rich view of the night sky. They’re lightweight, portable, and easy to use — perfect for quick sessions under the stars or for scanning broad swaths of sky without the need for alignment or setup.

Wide Views, Not Planetary Detail

Unlike telescopes, which are often designed for high magnification and narrow fields of view, binoculars provide a much wider perspective. This makes them ideal for observing large star clusters, the Milky Way, bright nebulae like Orion, or simply sweeping across dark skies to explore what’s out there. The experience of using both eyes gives a natural, immersive feel and often makes it easier to spot faint objects.

Binoculars are not intended for detailed views of planets or other Solar System targets — for that, a telescope is far more suitable. That said, you can spot some of the brighter planets like Jupiter and Venus with binoculars, and even glimpse the Galilean moons as tiny pinpricks around Jupiter. The Moon, of course, is a beautiful binocular target with plenty of visible detail.

Understanding Binocular Numbers

When choosing binoculars for astronomy, one of the first things to understand is the meaning of the numbers on the model, such as 10×50. The first number is the magnification (in this case, 10 times closer), and the second is the diameter of the objective lenses in millimetres — which determines how much light the binoculars can gather. For general stargazing, 10×50 binoculars strike an ideal balance: they provide enough magnification to reveal detail, while still allowing a wide field of view and remaining light enough for handheld use.

Giant Binoculars and Deep Sky Observing

Larger models like 15×70 or 20×80 — often referred to as giant binoculars — gather significantly more light and can reveal more subtle details in star fields or faint nebulae. These are much better suited to deep-sky objects, such as globular clusters, galaxy pairs, and diffuse nebulae that are otherwise hard to see. However, their increased weight and higher magnification make them difficult to hold steadily by hand. While some experienced users may manage brief handheld sessions with 15×70s, most will benefit greatly from using a tripod or monopod, which transforms these larger binoculars into powerful sky-scanning instruments. (There’s a separate section on mounts and tripods that will guide you through these options.)

The Importance of Lens Coatings

Optical quality is critical in astronomy, especially under dark skies where faint light matters. Good binoculars will be labelled fully multi-coated or FMC, meaning all air-to-glass surfaces are covered with multiple anti-reflective coatings. These coatings improve contrast, reduce internal reflections, and preserve as much incoming starlight as possible.

• Avoid binoculars with minimal or no coatings, as they tend to lose light and produce duller images — something especially noticeable when observing dim targets.

Porro vs Roof Prism Binoculars

The design of the prisms inside the binoculars also affects their performance. For astronomy, Porro prism binoculars are typically preferred. They have the classic offset “zig-zag” shape and tend to deliver better depth perception, brighter images, and wider fields of view than their more compact counterparts. Roof prism binoculars, with their straight-barrel design, are often lighter and more streamlined, but require higher precision in manufacturing to match the image quality of Porro models — which often makes them more expensive without a clear benefit for astronomical use.

Field of View and Image Stability

You’ll also notice that many binoculars advertise a “wide field of view.” This is more than a marketing term — a wider field allows you to take in large areas of the sky, which is especially valuable when viewing star clusters or navigating constellations. Higher magnifications narrow this field, which is why binoculars beyond 15× often require extra care in aiming and stabilising.

• For handheld use, stick to models with magnifications of 10× or lower. Anything higher typically demands support to avoid image shake and arm fatigue.

Why Zoom Binoculars Aren’t Ideal

Finally, while it may be tempting to consider zoom binoculars, which claim to offer adjustable magnification, they’re generally not recommended for astronomy. These models often suffer from narrow fields of view and reduced image clarity, especially at higher zoom levels. In low light conditions, such as under a night sky, they tend to perform poorly compared to fixed-magnification binoculars of similar size and quality.