Comparison Review: Four 10×50 and 12x50mm Binoculars

10×50 and 12×50 binoculars are often the astronomer’s choice for wide-field viewing. Credit: Jamie Carter

Ask any experienced amateur astronomer about sweeping the Milky Way or viewing larger objects like the Andromeda Galaxy and you’ll often hear the same reply. Get a pair of binoculars with 50mm lenses and leave the telescope for smaller objects. 

That’s useful advice because compared to smaller, more portable binoculars with 42mm objective lenses, 50mm binoculars are able to produce brighter images on the order of about a third of a magnitude. 

However, there are still some open questions. Binoculars with 50mm lenses are sold with a variety of power, most typically 10x and 12x, and using both the popular, compact roof prism and bulkier Porro prism designs. 

The benefit of a 10×50 over a 12×50 is the wider actual field of view, typically about 6.5º to 7.5° compared to 5° to 5.5° for a 12x model. You can also expect slightly sharper views from 10×50 binoculars purely because they’re lighter and easier to hold steady. While 12×50 means more power and a closer look at deep sky objects, it’s generally judged to be the maximum size stargazers should hold to avoid “wobbly stars” syndrome. After that it’s generally best to mount binoculars on a tripod. 

In this survey I tested a group of four low- to mid-priced models with suggested U.S. retail prices from $120 to $220, two with 10x and two with 12x magnifications. Two use roof prisms and two porro prisms, and together they create a mix of four products that are all inherently different. I present them here in order of price and power.


Nikon 10×50 Aculon A211

Nikon 10×50 Aculon A211 binoculars. Credit: Jamie Carter

Porro prism binoculars have become a byword for cut-price products, but this 10×50 example proves there’s still a place for good design as well as good value. Offering a 59.2º apparent field that’s impressively bright, there’s plenty of sharpness in the center, though with the inevitable (at this price) blur and slight darkening at the edges. Stars look reasonably sharp, albeit with a little false color, though beginners won’t notice either of these minor issues. 

Aside from green anti-reflective coatings there’s little here in the way of advanced glass, though it does use high-density BaK-4 glass prisms. Build quality is impressive for the money, with a smooth yet resistant focus wheel and textured pads on the underside of its rubber armor. They’re surprisingly lightweight, though like all Porro prism binoculars they’re relatively wide. 

In terms of versatility these binoculars also have a minimum close focus of 23 ft., which makes zero difference for astronomy, but may slightly limit their use for close birdwatching in a backyard. Great value and good performers for the price, the Nikon 10×50 Aculon A211 would make a good investment for an astronomy club looking for a few pairs of affordable binoculars for beginners. 

Bottom Line: Low-cost binoculars ideal for astronomy clubs. 

Pros: Wide field of view; great value.

Cons: Some edge blur; shortest eye relief of the group.

MSRP: $119.95

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Vortex 10×50 Crossfire HD

Vortex 10×50 Crossfire HD binoculars. Credit: Jamie Carter

Astronomy can be a pain in the neck. All binoculars come with a neck strap, but they’re never comfortable for more than a short period. Cue the waterproof Vortex 10×50 Crossfire HD, which features an intriguing GlassPak chest harness built-in to the padded case they ship with. It’s relatively small, of decent quality, and allows the binoculars to be easily clipped-in and clipped-out, though with the padded bag secured on the wearer’s chest. That arrangement won’t suit all users and its design lacks versatility because the harness and padded bag are permanently conjoined, but it’s a tempting extra feature on an otherwise attractive package. 

Boasting a 61º apparent field, these step-up 10×50 binoculars offer slightly warmer colors than the Nikon 10×50 Aculon A211. They also give more sharpness in the center, though there’s still a definite blur at the edges of the field of view. Built using BaK-4 glass prisms and HD glass to effectively reduce chromatic aberration, they also have multiple anti-reflective coatings.

The more compact roof prism design makes them lighter than the Nikon 10×50 Aculon A211, though only very slightly. What we didn’t like were the objective lens caps, which are tethered to the hinge. It makes them impossible to use, but they do flap around a lot while observing. 

Bottom Line: Good performers whose novel design makes them great for star parties and long stargazing sessions. 

Pros:: Waterproof; excellent build quality; sharp optics; novel GlassPak harness. 

Cons: Irritating tethered lens caps.

MSRP: $219.99

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Nikon Action EX 12×50 (CF) 

Nikon Action EX 12×50 (CF) binoculars. Credit: Jamie Carter

Extra magnification and extra toughness make for heavier binoculars. That’s immediately noticeable on the Nikon Action EX 12×50 (CF), which has a 12x magnification and – unlike the step-down Nikon 10×50 Aculon A211 – a waterproof and fog-proof build. Together it makes them, at 36.8oz, significantly heavier than the two 10×50 products on test here. That has consequences for easily holding them steady, so it’s good to see a tripod mount screw hole. 

They use the Porro prism design – something increasingly unusual on mid-range binoculars – which means the same limitation of 23 ft. close focus that affects the Nikon 10×50 Aculon A211. They have BaK-4 glass prisms and multi coated lenses, but where they differ from their more affordable stablemate is their eyecups, which at 11.8mm offer significantly more eye relief. However, they’re still not what I would call premium eyecups. I also didn’t like the focus wheel, which was rather stiff. 

Images are clear and crisp throughout the surprisingly wide 59.9° apparent field, with only a slight drop in sharpness at the edge of the field of view and no discernible drop in brightness despite the leap in power. 

Bottom Line: A good quality Porro prism binocular. 

Pros: Crisp images; tripod mount screw hole.

Cons: Heavy; stiff focus wheel. 

MSRP:  $189.95

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Celestron Nature DX 12×50

Celestron Nature DX 12×50 binoculars. Credit: Jamie Carter

It may seem slightly odd that the priciest, most premium binoculars on test here is also the only one to lack a tripod mount screw hole. After all, its 12x power makes it, on paper, an ideal candidate for some extra stability. However, its combination of advanced glass and a lightweight build makes it as easy to hold by hand as a smaller pair of 10×50. 

They weigh just 28.4oz, which makes them the lightest pair on test, but that doesn’t mean there’s a lack of build quality. It features softer, narrower eyecups that offer 0.56″ of eye relief. It also gives a significantly narrower field of view compared to the Nikon Action EX 12×50. 

The only binocular here to use Extra-Low Dispersion (ED) glass (Celestron’s proprietary fabrication), stars appear brighter through the Celestron Nature DX 12×50 than on its rivals here, with colors truer and more noticeable (such as when pointed at orangey star Arcturus). There’s no chromatic aberration or color fringing, which will appeal to purists, but best of all this high magnification binocular can easily be handheld.  

Bottom Line: A standout astronomy binocular. 

Pros: Extra-Low Dispersion (ED) glass; sharp, colorful, and bright images; compact and lightweight.

Cons: No tripod mount screw hole.

MSRP: $219.99

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TABLE: 10×50 and 12×50 Binoculars


Model Nikon 10×50 Aculon A211 Vortex 10×50 Crossfire HD Nikon Action EX 12×50 CF Celestron Nature DX 12×50
Optical design Porro Roof Porro Roof
Weight (g / oz) 900 / 31.7 863 / 30.4 1,045 / 36.8 806 / 28.4
Actual field of view (º) 6.5º 6.1º 5.5º 4.8º
Apparent field of view (º) 59.2º 61º 59.9º 48º
Eye relief (mm) 11.8 17 16.1 14.3
ED Glass No No No Yes
Phase-Corrected coatings No No No Yes
Interpupillary Distance (mm) 56-72 60-76 56-72 63-74
Waterproof No Yes Yes Yes
Dry Gas Filled No Nitrogen Nitrogen Nitrogen
Coatings Fully multi-coated Fully multi-coated Fully multi-coated Fully multi-coated
Tripod Mount Screw  Yes Yes Yes No
Warranty Limited lifetime Unconditional lifetime Limited lifetime Limited lifetime


About Jamie Carter

A science, travel and technology journalist for over 20 years, UK-based Jamie Carter writes for Forbes Science, Sky and Telescope magazine, the BBC's Sky At Night, Travel+Leisure and the South China Morning Post. He edits, leads tours to see eclipses, and regularly tweets about stargazing (@jamieacarter) and eclipses (@thenexteclipse).

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