Tips for Choosing the Best Binoculars for Stargazing


Greetings from the world of stargazing! A nice set of binoculars might be an excellent investment if you want to advance your stargazing abilities. With the aid of binoculars, you can see the stars, planets, and other heavenly bodies more clearly and find smaller objects in the night sky with more ease. Nevertheless, selecting the best binoculars for stargazing can be challenging given the variety of alternatives available. We’ll provide you with some helpful advice and things to think about while selecting the best binoculars for stargazing and the myths about space in this article. These suggestions can assist you in making an informed choice and locating a set of binoculars that suits your demands and budget, whether you are an experienced astronomer or just a beginner.

Features to Look for in Stargazing Binoculars

binoculars lens

Magnification and Aperture

When selecting a set of binoculars for observing the stars, magnification, and aperture are two important aspects when choosing a pair of binoculars for stargazing.

The term “magnification” describes how much a pair of binoculars can enlarge a picture of a far-off object. A pair of binoculars with a 10x magnification, for instance, will make an item appear 10 times closer than it would to the unaided eye. Higher magnification does not necessarily equate to improved image quality, though, as it can also enhance any trembling or hand movement.

The diameter of the objective lens, or the lens at the front of the binoculars, is referred to as the aperture, which controls how much light can pass through the binoculars. When using binoculars for stargazing, a bigger aperture can help gather more light, which can help to increase the brightness and clarity of faint objects in the night sky.

Generally speaking, while selecting binoculars for stargazing, both magnification and aperture are crucial considerations since they both affect the image quality and overall performance of the binoculars. Finding the ideal balance between the two is important since using an extremely high magnification with a tiny aperture may produce a dark, hazy image, while using a large aperture with a low magnification may produce photos with a wider field of vision but less information.

Specific magnification and aperture combinations that are suitable for stargazing

Your level of experience, the observing environment, and your personal tastes can all influence the precise magnification and aperture combination that is best for stargazing. However, as a general rule of thumb, stargazing binoculars with a magnification of 7x to 10x and an aperture of 35mm to 50mm can be a decent place to start.

Since higher magnification might amplify any shaking or movement in your hands, a magnification range of 7x to 10x is typically seen as a suitable compromise between magnification and visual stability. While still keeping the binoculars compact and lightweight, an aperture of 35mm to 50mm can offer sufficient light gathering power to make dim celestial objects visible.

You could prefer a higher magnification or larger aperture if you have more expertise watching the stars or if you have specific observation conditions (like black skies). Higher magnification may need additional support or stabilization to prevent image shake, and wider aperture binoculars may be heavier and bulkier as well. The ideal magnification and aperture ratio for watching the stars will ultimately rely on your own tastes and the observing environment.

Photo of black and yellow binoculars

Objective Lens Diameter

The diameter of a binocular or telescope’s front lens element, expressed commonly in millimeters, is known as the objective lens diameter. It is essential in assessing the instrument’s capacity to gather light, which is necessary for observing the stars.

You are frequently attempting to see dim and far-off things in the night sky when stargazing. Since they don’t produce much light, it can be challenging for human eyes to recognize them in the dark. A larger objective lens diameter will be useful in this situation. The more light an objective lens can collect, the brighter and more distinct the images will be.

In contrast to a pair of 10×25 binoculars, which only have a 25mm objective lens, a pair of 10×50 binoculars will have an objective lens diameter of 50mm. As a result, they can collect more light. When stargazing, having more light-gathering capacity can significantly improve your experience by enabling you to see fainter objects and features that would otherwise be invisible.

A larger objective lens, however, also corresponds to a larger, heavier binocular or telescope, which may be less portable and more challenging to handle. Furthermore, a narrower field of view brought on by a larger objective lens may make it more challenging to find objects in the sky. Therefore, depending on your observing needs and tastes, it’s crucial to strike a balance between objective lens diameter, image brightness, portability, and ease of use.

Specific objective lens diameters that are suitable for stargazing

Several elements, including your observing circumstances, level of experience, and personal preferences, can influence the particular objective lens diameter that is best for stargazing. However, as a general rule of thumb, a starting point for stargazing can be an objective lens diameter of 50mm to 70mm.

It is possible to make dim celestial objects visible using equipment that is still relatively portable and lightweight by using an objective lens diameter between 50mm and 70mm. Although they may be heavier, bulkier, and more expensive, binoculars or telescopes with objective lens diameters of 80mm or greater can produce significantly brighter and clearer images.

It’s important to keep in mind that a larger objective lens diameter also translates into a bigger exit pupil, which can have an impact on how bright the image you view is. The diameter of the objective lens divided by the magnification yields the exit pupil size, which is the size of the light beam that emerges from the eyepiece of a binocular or telescope. An exit pupil size of approximately 5mm to 7mm can be perfect for stargazing since it enables your eye to fully dilate and utilize the light captured by the objective lens.

The ideal objective lens diameter for watching the stars will ultimately depend on your budget, tastes, and observing conditions. When choosing a set of binoculars or a telescope for stargazing, it’s crucial to take into consideration factors like mobility, image brightness, and ease of use.

Man looking in binoculars during sunset

Prism Type

Prisms are used by binoculars to align the image seen through the lenses. The prism is an optical component that enables the binoculars to provide the viewer’s eyes with an upright and appropriately aligned image.

The two most popular prism types found in binoculars are roof prisms and porro prisms. Traditional porro prisms reflect the light path and produce an upright image by using a set of angled prisms. On the other hand, roof prisms employ several of internal reflections to produce a streamlined and compact binocular design.

The prism, which corrects the alignment of the picture seen through the lenses, is an essential component of binoculars. Without a prism, the image would be reversed and upside down, making it difficult to utilize, especially while monitoring moving objects like birds or other animals.

The quality of the image expressed to the viewer’s eyes in binoculars can also be influenced by the prism quality utilized in those devices. Materials like BaK-4 glass, which offers exceptional light transmission and image clarity, will be used to make high-quality prisms. On the other hand, poorer quality prisms might be made of inferior materials, which would reduce the light transmission and image quality.

Porro prism and roof prism

The two distinct prism types used in optical devices like binoculars, telescopes, and cameras to reflect and refocus light are porro prisms and roof prisms.

Ignazio Porro created the Porro prism in the 1850s, which is a particular kind of prism. It consists of a rectangular prism with two offset right-angled reflecting surfaces. Binoculars frequently employ the Porro prism because it offers a large field of view and depth perception. A Porro prism’s internal double reflection of the light path lengthens the optical path and increases the distance between the objective lenses and the eyepiece.

The 1870s saw the invention of the roof prism, also referred to as the Dach prism. It is a small, thin prism with two reflective surfaces that are at a 90-degree angle to one another. In a roof prism, the light path is twice reflected, but the second reflection occurs at the edge of the roof, creating a shorter optical path length and a more compact design. Due to their small size and simplicity of usage, roof prisms are frequently utilized in contemporary binoculars and cameras.

In optical instruments, both roof and porro prisms are utilized to create an upright, properly oriented image. However, due to their small size and shape, roof prisms are more frequently utilized in contemporary optical instruments.

Optolyth Alpin 7×42 binoculars

Recommended prism type for stargazing

A Porro prism is the suggested kind of prism for observing the stars. This is because, in comparison to roof prism binoculars, porro prism binoculars typically offer a broader field of view, improved depth perception, and brighter images. Furthermore, roof prism binoculars with comparable optical quality tend to be more expensive than porro prism binoculars.

There are telescopes that use Porro prisms in addition to Porro prism binoculars to provide an upright and appropriately oriented image. Refractor telescopes, also referred to as diagonal telescopes, use a Porro prism diagonal to rectify the image alignment.

Things to Consider When Buying Stargazing Binoculars

  1. Budget – Decide how much you are prepared to pay for a pair of stargazing binoculars. Since prices might vary greatly, it’s important to establish a budget before you go shopping. Remember that a variety of elements, like the magnifying power, size, weight, lens, and coating quality, can affect how much a pair of binoculars will cost.
  2. Good reviews – Look for binoculars that have received good feedback from other users. Online reviews of various models’ performance, dependability, and durability can be a great source of knowledge. You can make an informed choice about the binoculars to purchase by reading reviews.
  3. Eye relief – When using binoculars, eye relief is the space between the eyepiece and your eye. If you use spectacles, choosing binoculars with comfortable eye relief is extremely important. For increased comfort, select models with adjustable eyecups and binoculars with at least 15mm of eye relief.
  4. Quality – For the clearest and brightest images, look for binoculars with premium lenses and coatings. The clarity and contrast of the images you view through the binoculars might be impacted by the lenses’ quality. The kind of glass used, the number of lens elements, and the coatings used on the lenses are some aspects to take into consideration when evaluating quality.
  5. Extra accessories – Think about the extras, such as tripods, harnesses, and carrying cases, that come with the binoculars. If you intend to take your binoculars with you on outdoor trips, these extras can make using them simpler and more practical.
  6. Versatility – Choose a pair of binoculars that is adaptable enough to fulfill your demands if you plan to use them for other hobbies like bird viewing or hiking. While some pairs of binoculars are made exclusively for seeing the night sky, others are more versatile and may be used for a range of outdoor activities.



Budget, quality, eye relief, additional accessories, and versatility are just a few of the many variables that should be carefully taken into mind when selecting the best binoculars for observing the night sky. You can locate binoculars that offer the best value for your money and suit your particular stargazing needs by taking the time to research and compare various brands. Ultimately, buying a good pair of binoculars can improve your experience of stargazing and let you see the beauties of the night sky in more detail.