Ever thought about buying one of the best monoculars, instead of a pair of binoculars? For astronomy, a pair of binoculars are often considered as a portable and travel-friendly alternative to a small telescope. When it comes to monoculars you’re cutting down weight and bulk again. Weighing at least half as much as a pair of binoculars, a monocular is easy to carry around and great for hikes and long trips.
A single barrel design with only one lens, a monocular is essentially a mini-telescope, albeit often lacking the same level of magnification and features. Since there’s no need for two barrels to stay aligned and collimated, a monocular is a much simpler device than a pair of binoculars. Monoculars are mostly thought of as being for bird-watching, hunting and hiking, though a good monocular can have some astronomy use. If you’re serious about stargazing, you’ll need to stick to the best telescopes, or a set of good binoculars, but if space and weight is an issue, there are good options out there.
Although many smaller sizes have little more than a novelty use, there are plenty of monoculars available that have larger, objective lenses to let lots of light in, something that’s critical if you want to use them for any kind of astronomy.
About 40-50mm objective lenses are what to go for when choosing a monocular, along with 7-15x magnification, though there are other features to consider. Some monoculars have built-in image capture, others offer smartphone mounts for super-easy ‘digiscoping’ and/or a built-in tripod mount. Since you’re going to be using them outside it’s wise to choose a monocular that boasts waterproofing and fog-proofing, too. Here at Space.com, we’ve cast our eye over the market for the best monoculars and rounded up the essential picks for all kinds of astronomy.
Best monocular overall
Anyone after a basic pair of binoculars for stargazing is advised to look for a bare minimum of 7x magnification and 42mm objective lenses. That way you get enough of a close-up and enough light while also having binoculars that are light enough to hold steady. The same applies to monoculars, which makes the Opticron BGA WP 8×42’s 8x magnification and 42 mm objectives an excellent choice for backpackers, travellers and hikers looking for something to use on the go.
Easy for glasses-wearers to use, the Opticron BGA WP 8×42 are waterproof to 3m and nitrogen-filled, so fog-proof, and come with a handy leather carry case and a neoprene carrying strap. Thanks to the Opticron S-type multi-coating on the optical system it boasts plenty of contrast, clarity and a definite high-end feel. Sadly a wraparound mount is required to make the Opticron BGA WP 8×42 compatible with tripods. A 10×42 option is also available.
Best for weight saving
If you’re going to be travelling a lot and doing some occasional astronomy on-the-go there are few better options than the Hawke Endurance ED 10×42. Most importantly this BAK-4 roof prism monocular meets the minimum requirements for use at night, boasting 8x magnification and 42mm objective lenses. But being at the low end of those specifications means it’s as lightweight as possible at a mere 11.5 oz/325g.
Not that the Hawke Endurance ED 10×42 doesn’t have some heavyweight glass. It’s fitted with Hawke’s System H5 optics, with extra-low dispersion (ED) glass to reduce color fringing and multi-coated lenses. It comes with a waterproof chassis, protective lens case, lanyard, lens covers and a built-in 1/4-inch tripod thread.
Best for glasses wearers
A nitrogen-filled waterproof monocular, the Opticron Oregon 4 PC 8×42 roof prism product is all about wide-field viewing and top quality optics. With phase-corrected prism coatings and multi-coated optics the Opticron Oregon 4 PC 8×42 delivers clear, crisp views by day and in low light, with its 42mm objective lenses allowing just enough light in for general astronomical use. That 8x magnification isn’t much, but that guarantees you a good (and stable) view when sweeping the Opticron Oregon 4 PC 8×42 across the star-fields of the Milky Way.
The design incorporates an external focuser for easy single handed operation, though it does lack a built-in 1/4-inch tripod adaptor. Wearers of glasses will appreciate its generous 22mm of eye relief.
Best for accessories
If you’re after something with exceptional optics, build quality and extras then look no further than the Bushnell Legend Ultra 10×42, which easily lives up to its name. Bushnell’s ED Prime HD glass used inside the Bushnell Legend Ultra 10×42, together with multi-coated and anti-reflective optics, means crisp, detailed images while its 42mm objective lens allows enough light in for basic astronomy duties.
As a bonus its twist-up eyecups offer lots of eye relief to wearers of glasses and there’s even an easy-grip ridge on top of the external focuser where a thumb naturally rests. Unlike most products in this commodity market the Bushnell Legend Ultra 10×42 ships with a top quality padded case (complete with belt clip), a flip-style lens cap for the front and a rear lens cap that attaches via a lanyard to prevent it from getting lost.
Best for magnification
There are a lot of smartphones coming onto the market now offering super zooms, some even with dedicated ‘moon zoom’ modes. However, they all use AI and digital zoom because smartphone lenses are just too tiny. Instead of upgrading a smartphone, one option is to use something like this BAK4 roof prism-based lens for its superior optics. Essentially a monocular with a fixed zoom of 36x, the Apexel 36x super zoom can be used hand-held, but is at its best when on a tripod. You then fit a clip around your smartphone’s lens before attaching it to the Apexel 36x super zoom to bring them into alignment.
It’s not a perfect system since you first need to remove a smartphone’s case, there’s no tripod thread built-in (a metal tripod ring adaptor is supplied) and in any case the tripod it can be bundled with is flimsy. Supply your own tripod and the Apexel 36x super zoom can be an adequate set-up for taking basic images of the Moon (though don’t expect it to fill the field of view). It can also be used as a straight-up monocular by attaching a small rubber eyepiece, though the field of view is restricted.
Best for using with a smartphone
Taking astronomical photos at night isn’t easy. In fact, don’t buy the Celestron Outland X 10×50 just for that. Yes, it comes with a smartphone mount and, yes, that turns the Celestron Outland X 10×50 into a ‘digiscoper’, but it’s only going to work well for the occasional photo of the Moon.
What you do get with the Celestron Outland X 10×50 are astronomy-centric optics. With 10x magnification and 50mm objective lenses the Celestron Outland X 10×50 is well suited to searching for, and studying, open star clusters and the Milky Way.
Built around BAK-4 prisms, the Celestron Outland X 10×50 feature multi-coated optics and have plenty of eye-relief, so can be used easily by anyone who wears glasses. It’s also waterproof and filled with nitrogen gas to prevent internal fogging.
Best for travelling light
If you’re after something versatile that’s capable of both observations and basic photography then consider the Olivon 8-24×40. A small and lightweight monocular, it’s able to magnify from 8x right through to 24x. With that kind of magnification it’s a great option for observing the Moon’s craters and lava seas.
A BK-7 prism-based monocular, it comes with a built-in 1.4-inch tripod adaptor, easy-grip rubberized coating and multi-coated optics and can also be used as a basic digiscoping option. When used for wildlife the Olivon 8-24×40 offers close focus from 60”/1.6m. It comes with a lanyard and a small pouch.
Best for Moon-viewing
Slightly pricier than the Olivon 8-24×40 is the Orion 10-25×42, another variable zoom monocular than offers from 10x through 25x magnification. As such it’s also a great option for lunar viewing, with just a touch more magnification than its lighter rival. Since it doesn’t have quite as wide an angle of view it can focus on subjects just 20”/half a metre away while also offering 25x magnification for glimpsing craters on the Moon. It’s also usable during low-light thanks to its 42mm aperture objective lens.
Waterproof with a rugged, rubberised design, the Orion 10-25×42 features multi-coated optics and ships with a soft nylon case (complete with belt loop) and a wrist-strap.
Best for wildlife
More magnification is always tempting when it comes to astronomy, but it comes with cons as well as pros. With a stunning 15x magnification the incredibly expensive Vortex Recon R/T 15×50 will give you a much closer look at objects than your average pair of astronomy-centric binoculars and monoculars. In the daytime that’s great! At night, not so much. That extra magnification creates a narrow exit pupil, which reduces the brightness of the image despite the Vortex Recon R/T 15×50’s boasting large 50mm objective lenses.
So what is the Vortex Recon R/T 15×50 for, astronomically? The Moon. With multi-coated extra-low dispersion glass expect detailed and high-resolution images at long distances. A nice detail is that it comes with a hand-strap but also with a carry clip that attaches to a belt, clothing or a bag. However, this is primarily a pricey accessory for wildlife-spotting.