What's more, a good pair of binoculars can be used just as easily during the day, so if you're on vacation you can use them for animal and bird watching as well as stargazing. What we love about the best binoculars is that they don't cost the earth. While many of the best telescopes can run up to hundreds of dollars, and aren't as portable, binoculars are a far less expensive option. True, you don't quite get the same magnification, but they're so much more portable and versatile. Another advantage is that they often have a wider field of view, so you can take in more of the night sky at once.
Stargazing using binoculars requires a little skill, and you have to know how to hold your binoculars to avoid aching arms, but generally speaking there's no real barrier to using them. Even the most amateur of astronomy enthusiasts can use them to watch the night sky, and start seeing things clearer during the day too.
When buying binoculars we recommend you look for at least a magnification of 7x or 10x, and you choose a Porro prism design. Fully multi-coated optics are a must for crisp and clear observations. While weight is an issue and if you buy larger binoculars, you could invest in a tripod to steady them , there are ways to hold them that allow steadier skywatching. Here are our selections of the top-rated binoculars of Ask any seasoned astronomer which is the best binocular magnification for getting started in skywatching and the answer will be 10x However, the TrailSeeker 8x42 from Celestron offers a slightly different view to the norm — and it's all down to the amount of light the 42 mm apertures collect during observations.
What's more, the lower magnification offers a wider field of view over 10x50s. While the moon , for example, appears a touch smaller through this binocular than through the barrels of 10x50s, the optical system combined with multi-coated optics offers a much crisper and brighter image. Another advantage of the Celestron TrailSeeker 8x42 is the lack of false color — also known as chromatic aberration — which often takes the form of a purple or blue hue around brighter targets.
Very little is detected in the field of view, particularly along the limb of the moon, as we studied a plethora of craters, rilles and lunar mare on its rugged terrain. Star clusters such as the Beehive Cluster Messier 44 in Cancer the Crab , look stunning through the TrailSeeker 8x42 — like jewels studded in a velvet-black background. Meanwhile, Venus appeared as a bright disk with no false color. The TrailSeeker 8x42 binocular is also quite light at 2 lbs.
But over long periods of observing time, we discovered that our arms began to shake making it difficult to get a steady hand-held view: if you're prone to trembling arms, a tripod is definitely a recommended accessory.
Sometimes, when optical instruments are being designed, consideration is not always given to astronomers who wear spectacles. These observers often find that their eyes cannot get as close to the eyecups or eyepieces of binoculars and telescopes, forcing them to remove their glasses for a comfortable view.
The Opticron Adventurer II WP 10x50 binocular is the perfect solution for spectacle wearers, since an excellent eye relief of 0. The binocular also features twistable eyecups that can retract or extend, making the Opticron Adventurer II WP 10x50 more comfortable, whether you wear glasses or not.
So how about the view? The optics are excellent and provide great contrast, showing all the usual suspects well: open star clusters like the Pleiades Messier 45 in Taurus the Bull and the Beehive Messier 44 in Cancer the Crab were picked out with ease and are viewed with high clarity, while bright double stars — particularly Mizar and Alcor in the constellation of Ursa Major the Great Bear — resolve well under the magnification.
Additionally no fogging was noted during our observations and during tests under a variety of temperatures. The sturdy, well-constructed Vortex 10x50 Crossfire HD binocular is primarily intended for terrestrial observations or watching wildlife in action.
That's not to say that they can't be turned skyward, though. Through the field of view, the sights are crisp and clear, with stars appearing as perfect pinpoints of light. However, we did detect a degree of false color when observing brighter targets: the moon and Jupiter , for example, were tinged with a blue-to-purple hue around their outer edges — it's worth noting that this optical defect isn't unusual at this price point.
Additionally, our views of the night sky were not ruined and we enjoyed our tour with the Vortex 10x50 Crossfire HD. In terms of build, this binocular is well-constructed with a solid, heavy-duty focusing knob that's a breeze to adjust even when wearing thick gloves to fend off chilly winter temperatures. An added bonus is that the eye relief is adjustable thanks to twistable eyecups, allowing the skywatcher to find a setting that's most comfortable for observing.
The Celestron SkyMaster 25x binocular is truly like a pair of giant telescopes: touring the heavens with them is like viewing the night sky using two four-inch mm refractors, with added 25x magnification. At The eye relief is decent at 0. While sweeping through the Milky Way, particularly the dense star fields of the summer Milky Way in Sagittarius is a sight has to be seen to be believed: gaggles of stars dominated the field of view, especially when we hit the Sagittarius Star Cloud Messier We could grip the barrels with ease, thanks to the binocular's ultra-firm rubber grip.
The multi-coated optics are exquisite, with bright images and stunning contrast. The moon and its craters, rilles and mare look outstanding in the three-degree field, with the only real downside in the optics being a slight false-color fringe around brighter targets. Considering the aperture gathers as much light as a single 6-inch refractor but for far fewer dollars, the Celestron SkyMaster 25x binocular is highly recommended — especially if you're on a tight budget.
However, the larger the effective diameter, the heavier the binoculars become. The maximum diameter for handheld binoculars is about 50 mm. The pupil of binoculars appears as a bright circle when viewed about 30 cm away from the eyepiece lenses. This size is known as the "exit pupil diameter". The exit pupil diameter can be calculated by dividing the effective diameter of objective lens mm by the magnification x , and the relative brightness of a pair of binoculars is expressed using "exit pupil diameter mm " 2.
The larger the exit pupil diameter, the brighter the image in the binoculars will be. As a rule, if the exit pupil diameter of binoculars is larger than the pupil diameter of the human eye, the image in the binoculars will appear bright. Conversely, a smaller exit pupil diameter will make the image in binoculars appear darker than when a scene is viewed with the naked eye. The pupil diameter of the human eye changes significantly due to brightness and age, opening to about two to three mm in bright locations, and from five to seven mm in dark locations.
For this reason, binoculars with the exit pupil diameter of about two to three mm or more are good for use in bright locations, whereas five to seven mm or more are best for use in dark locations. In bright locations, the human pupil diameter opens from about two to three mm. The 8x25 WP II waterproof binoculars with the exit pupil diameter of 3. Because the human pupil diameter in dark location is about five to seven mm, binoculars with the exit pupil diameter of five mm or higher, such as the 8x42 PRO pupil diameter of 5.
This term indicates the visible range of binoculars from a fixed position, and is expressed by the angle measured from the centre of the objective lenses. The wider the actual field of view, the easier it is to find objects. As the magnification of the binoculars increases, the actual field of view narrows. This indicates the range in meters visible 1, meters ahead when binoculars are in a fixed position. This is the visual angle when looking through binoculars.
A wide apparent field of view indicates a wide actual field of view even at a high magnification. Even at the same magnification, a wide view type with a wide apparent field of view delivers images with greater impact. The basis for wide view type binoculars differs depending on the standard.
This is the distance from the final surface of the eyepiece lenses to the eye at which the entire field of view is visible through binoculars without vignetting. If this distance is long, it is easier to use binoculars even while wearing glasses. The shortest distance where focusing is possible on binoculars is called the closest focusing distance.
When observing close-up subjects such as flowers and insects, a pair of binoculars with a short closest focusing distance is best, such as the 8x42 PRO and 10x42 PRO with a closest focusing distance of 1. When light passes through the lens or prism, it reflects off the surface, reducing the amount of light, making the image appear darker. Anti-reflective lens coating is applied to the surface of the lens to prevent loss of light. There is single-layer mono-coating, and multi-coating, which is formed of multiple layers.
Lenses with multi-coating have higher light transmittance, resulting in a bright, clear field of view. Many current binoculars use convex lenses for the objective lenses and eyepiece lenses and a prism to erect the image. This feature can often go unnoticed by novice users who aren't certain what it does. Follow these five easy steps and you'll get the best image possible:. Look through your binoculars at a plain scene, such as grass or sky, and move the central hinge until you see a single bright circle.
Cover the barrel that has the dioptre adjustment on its eyepiece. This is usually on the right-hand side. Look at a fixed object in the distance, then use the central focusing wheel to focus the binoculars until the image appears clear and sharp. While looking at the same image, cover the left barrel. Use the dioptre adjustment on the right eyepiece to make the image appear clear and sharp. Binoculars can often be described in baffling language.
While you don't need to know everything about their anatomy, an understanding of some of the key terms and features will help you get the best out of yours.
W Which? Editorial team. In this article Questions to consider before buying a pair of binoculars Types of binoculars Binocular features to look out for Where to buy binoculars Popular binoculars from major retailers How to focus binoculars Binoculars terminology explained.
At what time of the day will you use your binoculars? The objective lens diameter is the measurement of the lenses at the end of the binoculars.
A larger objective lens diameter lets in more light, making the image appear brighter all other factors being equal. The exit pupil tells you how much light is sent to your eye through the binoculars and is calculated by dividing the size of the objective lens by the magnification.
The light-transmission measurement will tell you what percentage of light reaches the eye after entering the binoculars. The lens coatings used can help reduce the amount of reflected light and increase the amount that reaches the eye.
This helps improve the brightness and clarity of the image. Do the binoculars need to be lightweight and compact? Related articles Backpack buying guide Sleeping bag buying guide How to buy the best walking shoes How to buy the best waterproof jacket. Share on Facebook Share on Twitter Share by email. Latest News In Which? Travel update: all countries removed from red traffic light list — where can I go on holiday?
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