Binoculars Buying Guide

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What are binoculars?

Binoculars are two identical telescopes ganged together so that a person can look through them with both eyes simultaneously, providing a three-dimensional image similar to what would be seen without the use of binoculars. Using both eyes is also more comfortable and more natural compared to using a telescope, for which one eye has to be closed to see properly.

Why do prices vary so much between similar pairs of binoculars?

There can be a huge range in price between apparently similar pairs of binoculars. For example, B&H sells 10x42 binoculars ranging in price from $30 to $2,500. The main reasons for such a huge price range are the brand, the quality of the optics, the types of coatings applied to the lenses and other features that might be added.

Why do some binoculars look more streamlined than others?

If you’ve been studying the design of different binoculars you might have noticed that some look very streamlined while others look chunkier and heavier. That’s because the physical appearance and size of a pair of binoculars is determined by the type of prism they use. There are two types of prisms: roof and porro. The glass elements in a roof prism are in line with one another, making roof-prism binoculars more streamlined and easier to hold. Porro prisms have the glass elements offset from one another, providing greater depth of field and a wider field of view, but at the expense of a bigger, heavier design.

Why do binoculars contain prisms?

Prisms are used to present an image as right-side up and laterally correct; without a prism, binoculars would make things look upside down and flopped.

What do the numbers mean?

Binoculars use numbers such as 10x42 and 7x20 to indicate their magnification power. Using 10x42 as an example, the 10x means that the binoculars offer 10x magnification power; in other words, things appear 10 times closer than they do with the naked eye. Everyday binoculars should be between 7x and 10x power. Theatergoers should choose 7x while big-game hunters would need 10x or higher. Keep in mind that anything higher than 10x is very difficult to hold steady without a tripod.

The 42 in our 10x42 binoculars refers to the diameter of the objective lens. It also dictates the thickness of the binoculars, or the diameter of each cylinder, and how much light is able to pass through them. If you know anything about camera lenses, you know that the larger the maximum aperture, the more light gets through them, which allows the camera to take acceptable pictures in low-light situations. It’s the same with binoculars; the larger the objective lens, the more light gets through and the brighter and more detailed the image will be.

Like a zoom lens, zooming binoculars offer variable magnification. Binoculars designated as 10-30x60 offer 10x magnification at the low end and 30x magnification at the high end. There’s usually a thumb lever or wheel that lets you adjust the magnification level.

What is an exit pupil diameter?

The objective diameter also determines the exit pupil diameter, which should always be larger than the pupil of your eye. The pupil of a human eye ranges from about 1mm in bright conditions to about 7mm in the dark. If your binoculars’ exit pupil diameter is smaller than the pupil of your eye, it’s going to seem like you’re looking through a peep hole.

A binoculars’ exit pupil diameter is determined by dividing the second number by the first. So a 10x42 pair of binoculars has a 4.2mm exit pupil diameter. That’s a generous size, and larger than the pupil of the eye most of the time. But a 10x25 pair of binoculars has just a 2.5 mm exit pupil diameter, which is smaller than the pupil of the eye most of the time and will be harder to see through clearly.

Zooming binoculars might have a perfectly acceptable exit pupil diameter under low magnification but one that’s somewhat small under high magnification. For example, 10-30x60 binoculars have 10x magnification at the low end and 30x magnification at the high end. At 10x the exit pupil diameter is a respectable 6mm, but at 30x it’s only 2mm.

What’s the difference between waterproof and fog proof?

Many binoculars have no weatherproofing, while some are waterproof and others are waterproof and fog proof. Binoculars that have no weatherproofing should not be used in the rain or at sea, as moisture can get inside them, rendering them useless.

Waterproof binoculars are sealed with O-rings to prevent moisture from getting inside; but they can still fog up on you. Fog-proof binoculars are air- and water-tight, and filled with pressurized nitrogen gas to prevent fogging. Not all waterproof binoculars are fog proof, but all fog proof binoculars are waterproof.

What is the angle of view and field of view?

The terms “angle of view” and “field of view” are almost interchangeable. Both terms describe the amount of scenery, measured horizontally, that is visible when looking through a particular pair of binoculars. Angle of view is expressed in degrees. Imagine standing in the middle of a giant pizza pie; binoculars with a 6.3-degree angle of view would show the viewer a 6.3-degree “slice” of the 360-degree pie, looking outward.

Field of view is expressed in feet, at a distance of 1,000 yards. For example, say you’re looking at a ship that’s 1,000 yards away; binoculars with a 330-foot field of view would show you 330 feet of the ship, measured horizontally.

What is eye relief?

Unlike an ice pack for a black eye, eye relief for binoculars takes the form of eyecups that block extraneous light and eliminate glare, and also keep the viewer’s eyes a specific distance from the eyepieces. If you’re wearing glasses, the glasses will hold the eyepieces away from your eyes so that you no longer can use the eyecups.

Simple eyecups fold away from the eyepieces when needed, and fold back snugly against them when not needed. Fancier binoculars will have adjustable eyecups that twist in and out to set the proper distance for the individual user.

How does eye relief affect field of view?

Eye relief does not come without a cost, and this is the field of view. You’ll generally find that those models with more eye relief have a smaller field of view at 1000 yards than similarly priced models with less eye relief. Accomplishing superlative statistics in both categories is an expensive process of optical engineering. It is always good to have a broad viewing area, so decide how much eye relief is necessary for you and buy the binoculars that otherwise give the widest field of view.

What is dioptric correction?

People’s eyes do not possess identical vision. Sometimes one eye sees better than the other. Dioptric correction is an adjustment that lets you obtain precise focus for both eyes. Binoculars with dioptric correction will have an adjustment on one of the eyepieces that is used to compensate for differences between the two eyes. Basically you set the dioptric adjustment to neutral, or center, and use the main focus wheel to adjust for perfect focus in the eyepiece that doesn’t have dioptric correction. Then you adjust the dioptric eyepiece so that eye also sees a properly focused image.

What are rangefinder binoculars?

Rangefinder binoculars contain battery-powered circuitry and a laser that’s used to measure distance from the binoculars to the object that’s in focus. They can be used at sea to measure the distance to another ship, or possibly, someone that needs rescuing. Or they might be used by game hunters to measure the distance to their prey. They can help golfers calculate their swing from the sand trap to the next hole. Rangefinder binoculars typically display the distance to the target in either feet or meters, with the readout visible in the eyepieces.

What are stabilized binoculars?

In the same way that digital cameras can have image stabilization, so too, can binoculars. Image stabilization compensates for operator movement, the swaying of a boat or the vibration inside a helicopter, thus presenting the viewer with a steadier image. Stabilized binoculars might contain a gyro that requires power to provide stabilization or perhaps a pendulum-type device that provides stabilization without being powered. In general, the larger the exit pupil diameter, the less important stabilization becomes.

What is a tripod mount?

As mentioned before, binoculars that are 10x and higher are hard to hold steady, especially if they are big and heavy. Large binoculars should have a built-in tripod mount that makes it easy to mount them on a tripod. Sometimes a tripod adapter is required.

What do lens coatings do?

Lens coatings, as the term implies, are coatings applied to lenses to eliminate glare and reflections, increase contrast and make colors look more vivid. Any light reflected is light that never reaches the viewer’s eyes, so by eliminating reflections, you also end up brightening the image.

Coatings in general are good, provided that the coatings do something. It’s easy to put a cheap coating on a lens to give it a cool-looking orange tint, but the coating might not do anything to improve image quality. If you aren’t able to test out a pair of binoculars before buying, the best you can do is research the brand, look for user reviews and ask questions before you buy.

It’s a good bet, too, that $50 binoculars will be worth about that much, no matter how impressive they look. A pair that costs $1,000 or $2,000 will likely perform many times better than inexpensive ones. But inexpensive is definitely much better than none at all.

The Takeaway

  • The glass elements in a roof prism are in line with one another, making roof-prism binoculars more streamlined.
  • Porro prisms have the glass elements offset from one another, providing greater depth of field and a wider field of view, but at the expense of a bigger, heavier design.
  • Everyday binoculars should be between 7x and 10x power. Theatergoers should choose 7x, while big-game hunters would need 10x or higher. Anything higher than 10x is difficult to hold steady without a tripod.
  • Using 10x42 as an example, the 10x means that the binoculars offer 10x magnification power. The 42 refers to the diameter of the objective lens; the bigger the objective lens, the more light gets through and the more useful they will be in low-light situations.
  • Zooming binoculars offer variable magnification. Binoculars designated as 10-30x60 offer 10x magnification at the low end and 30x magnification at the high end.
  • Waterproof binoculars are sealed with O-rings to prevent moisture from getting inside.
  • Fog-proof binoculars are air- and water-tight, and filled with pressurized nitrogen gas to prevent fogging.
  • Angle of view is expressed in degrees.
  • Field of view is expressed in feet.
  • Eyecups block extraneous light and eliminate glare, and also keep the viewer’s eyes a specific distance from the eyepieces.
  • Dioptric correction is an adjustment that lets you obtain precise focus for both eyes.
  • Rangefinder binoculars contain battery-powered circuitry and a laser that’s used to measure distance from the binoculars to the in-focus object.
  • Image stabilization compensates for operator movement to present a steadier image.
  • A tripod mount makes it easy to mount binoculars on a tripod for stabilizing.
  • Lens coatings eliminate glare and reflections, increase contrast and make colors look more vivid.

Items discussed in article

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Clear, concise and easy to understand. The variety of content is very helpful. Thank you.

As someone who knows nothing about binoculars but needs (wants) some, this is exactly the information I was looking for. Easy to understand, too! Many thanks for the article!

Excellent. Everything I needed to know and summarized perfectly in the end for a takeaway. Thank you.

Exactly the information I needed.
clear and concise. Thank you!

Very nice article. Covers all the main topics I wanted to know about.

Excellent article. Very clear and informative

Fabulous article - the perfect guide for both the amateur and experienced binocular buyer! Thanks!

Good article. It helped me understand the terms easily and helped me buy a pair of binoculars best suited for my needs.

In laymens terms so anyone can make sense and buy correctly.

I was about to buy what I do not need! Cheers for this article. Thank you!

Brief, yet methodical in narration and rich in content. Thanks Mr Spiwak

Excellent article and guide with simple and rich contents, helps to any buyer who may be completely unknown to binoculars and terms connected to it.
Thanks for sharing !

Gives you nice information on what to look for and decide your needs when choosing binoculars.

Excellent buying guide, really helped me educate myself on the various technical facets. But wish it had some recommendations too for different categories (travel, sports, theater etc.)

Hi,

I want to watch Bird and Sky both. So should I buy 10x50 DPS I 10x Binoculars or 8 - 16 x 40 Zoom DPS I 16x Binoculars ?? I am in confused. Seek guidance from experienced persons.

Thanking you.

Thank you..This a real piece of information!!! Thanks for taking time to educate us about the technical side of the binocular.

Hi I am looking at binoculaors wich says they have 1000% or 10x magnification and 25 mm aperture with 3.7 degrees field of view. are they considered high power? they are for abt 60 dollars. I am trying to find out if they are highly priced.some information will be helpful. thank u

So any recommendations for a sports fan who would use them for formula 1 one racing and to look at boats and such when sitting on the beach?? He is older and wears glasses so they need to be adjustable for his bad eyes and mine that are still OK.
Looking to spend max $ 250.

What would you recommend
I am looking for binoculars to use on the beach, while kayaking, and at sporting events. I would like waterproof.
Preferably under $100.
Thank you

My son in law asked for a pair to use at the football games. Any suggestions?

I would like to buy my husband a pair of binoculars to use on our boat. He wears glasses and has always had trouble seeing clearly out of binoculars in the past. My father has a pair of fujinon marine binocs. that for some reason he can see clearly out of but unfortunately they are old and I can't find the same model. I don't want to spend more then necassary but would def. like to keep it under $300. Any ideas?
Amy

I am looking for a pair of binoculars that has great magnification, for viewing on the water, but is pretty lightweight. I need to carry them with me. Not too expensive.

You do not mention auto-focus (or Focus Free) in your guide. My past experience with binoculars has been very bad with respect to quickly focusing on the subject (wild life) when going on a safari. I would like to find a small/light, auto-focus binoculars for use when traveling and looking at birds/wildlife. Any suggestions?
thanks.

thank you for your time and effort placed into your in-depth research. for the rookie like myself who after going to the store (without any knowledge) and left frustrated knowing that there was a science to the art, i can now go back with the invaluable information and make a better decision. thanks again and merry Christmas.

Great article ! Thank you !

Precise, concise, clair. Job well done.

Félicitations !

Thanks for the great explanation for what to look for in binoculars.  It was very helpful!

Thanks for a very informative article.  Bought binoculares and after reading this article I'm returning them foir some that are a bteer fit.

Thank you so much for this wonderful and informative article. I learned a lot.

Thank you. This was very helpful and had just the right amount of detail.

Thank you for all the helpful infotrmation on binoculars. We are going on a land and cruise trip to Alaska this summer and wondered what you would reccomend?

Hi Debbie -

Below are several recommendations based on your criteria. All of these binoculars would be suitable for your trip.  Please note the differences in size and weight and consider what may be comfortable for you to hold and carry along.  See the links below for details:

http://bhpho.to/1c1xqVr

http://bhpho.to/1bQ1qPH

http://bhpho.to/19yyq2W

http://bhpho.to/1gGFles

Please contact us via e-mail if you have additional questions:  AskBH@BandH.com

Wow! Great source of complete information

Thank you so much for writing this article! I have been looking for months for someone to explain just a little of this in a way that I could retain it. You have done just that! Thank you Thank you Thank you! And though he doesn't know it just yet, my husband thanks you.....a gift. 

This was extremely Helpful!

Exceedingly helpful info for a binocular novice. I need to replace binoculars lost in a house fire, binoculars that came from my parents. So I've never bought serious binocs before. This info was clear, concise, and written in a way I could understand without feeling talked down to. I was impressed enough that this site was bookmarked before I got 1/2-way through. Thanks for the help!

I have a pair of binocs that are Sard 7X50 US Navy. They need repairs such as cleaning,lubrication, alignment two eye piece diopter/retainer rings and two eye cups. The cost of repairs is about $175.00.

My question is are they worth it? ANy comment?? Thank You

The Sard 7X50 is a vintage binocular from the 40’s. You could find them online from $75 to $350. So it is hard to say if they are worth repairing. As a vintage item it might be a good collector’s item. But with new developments in optics and binocular design your money would be better off buying a new pair. The Nikon 7x50 Action Extreme ATB Binocular has new modern lens coatings, BAK4 Porro Prisms, and is nitrogen-filled fog-proof and waterproof.

Really good knowledge....I want to get knowledge about different types of best gadget and also include the best and top brand of that gadget and price....thnx. Really interesting u are....mean site organiser

This article is comprehesive and helpful in deciding which binocular to buy.

Thanks

binoculars range how can chack in KM.

The magnification of a binocular is how much closer an object will look than your eye. So if you have a binocular with a 10X magnification and the object is 50KM away, the object will appear in the binocular like it is 5KM away.

I live in a 4th story condo and I see quite a few different animals,  I have a cheap pair of 30x60 and need something better.

I would like to stay aroung 100.00.  Please help  Thanks.

I would suggest the Celestron LandScout 12-36x60 Spotting Scope with Tripod.  In that price range, a scope will likely give you better results than another set of binoculars.