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How To Choose Binoculars : A Complete Guide Of Choosing Binoculars For Different Applications

Welcome to Binoculars Guru's - A Definitive Guide of How To Choose Binoculars for different applications; what you need to know. In this guide, you will learn the bull's eye criteria that you must need to keep in mind before going to shop for binoculars. This guide is designed for Hunter, Bird Watcher, wildlife viewer, Safari lover, hiker, astronomy & Stargazer and the Military person who must need binoculars. By the way, If you are in a hurry and don't want to read the full guide, Then I will advise you check out the table of the content section or quick reading options below for your specific needs.

Let's dive into it...

 How To choose binoculars

When you go binocular shopping, expect to be bombarded with a wave of options of varying prices and features. Also, expect to part with a substantial amount of money if you want a good quality pair of binoculars. Especially since a pair of binoculars is a long-term investment that should pay off. Therefore, when shopping for binoculars, it is important that you know what to look for. Essentially, it is important to learn how to choose binoculars.

Also Read: Common Mistakes Beginner Make While Choosing Binoculars 

Different types of binoculars appeal to different users. Thus, your choice of binocular will depend on how you intend to use it. Also, it is important to know the different terminologies used in reference to binoculars. These terminologies include : field of view, exit pupil, eye relief, aperture, and Interpupillary distance. Let us look at each one of these terminologies individually.

Basic And Advanced Terminology That You Need To Understand

how to choose binoculars

What is Magnification in Binoculars?

Binoculars are referred to by their magnification, which is how much a binocular magnifies an object. For example, if a binocular has an 8X magnification, it means it will make the far away object appear 8 times larger than they would if you looked at them with your naked eyes.


Binocular lenses are manufactured from glass materials. Therefore, you are likely to encounter several terms relating to lenses when shopping. One of the most common terms used is extra low dispersion glass. Lenses made using this type of glass offer clearer and sharper images. Thus, I recommend going for binoculars whose lenses are made using either extra low or low dispersion glass.

Some manufacturers use specialized glass materials called eco-glass. These materials are usually free of arsenic and lead. So if you are cautious about the environment, then binoculars with such types of lenses will appeal more to you.

As for the prisms, binocular prisms are crafted from either Bak7 or Bak4 glass. Bak4 is costlier than Bak7 glass and is of a higher quality. Thus, many high-end binoculars are fitted with Bak4 prisms while mid-level Binoculars feature Bak7 prisms. Bak4 prisms transmit light better and minimize loss of light through reflection.

So how do you know whether a binocular has a Bak4 or Bak7 glass?

There is a simple test you can do. This test entails holding the binocular some 6 to 8 inches away from and looking through the objective lens. If when you look you see a squared-off image, then that is a Bak7 glass. But if you look and the image appears rounded, then that is a Bak4 prism.

What is Anti-Reflective Coatings in Binoculars?

Anti-reflective coatings are thin, transparent films applied over a binocular’s glass surface. The purpose of these coatings is minimizing reflection of light. Thus, these coatings improve a binocular’s light transmission and image brightness. Binoculars can be coated, fully coated, multicoated or fully multicoated. Coated lenses have one layer of antireflective coating on them. Usually, only the outer glass surfaces are coated. Fully coated on the other hand means that all glass surfaces are coated. Multicoated means that the outer surfaces are coated with several layers of antireflective coating. Fully multicoated means that all glass surfaces are coated with several layers of antireflective coating.

Roof vs. Porro prism binoculars

One of the most heated debates among binocular users is which type of binocular between Roof and Porro prism binocular is better. Porro prisms ruled the binocular market before the introduction of roof prisms binoculars in the 1960s. By definition, a roof prism binocular is one whose eyepiece and the objective lens are in a straight line. This means that light goes straight to the eyepiece through the objective lens. Porro prism binoculars, on the other hand, have a zig-zag design.

Roof prism binoculars are lighter and more compact that their Porro prism counterparts. However, roof prism binoculars are more complex and thus are more costly than their traditional Porro prism counterparts. Personally, I prefer room prism binoculars to Porro prism binoculars. However, Porro prism binoculars are cheaper and offer greater value for money. Additionally, thanks to advancements in technology Porro prism binoculars are today able to compete with their room prism counterparts. Also, modern Porro prism binoculars are lighter than their earlier counterparts. Thus, the type of binocular you choose will depend on your budget and preferences.

Relative Brightness Index

Theoretically speaking, relative brightness index refers to how bright an object ought to be when viewed through a binocular. This index is got by squaring the exit pupil. So let us say a binocular has an exit pupil of 6.25, its relative index will be 37.5. I have arrived at this number by multiplying 6.25 by 6.25.

What is Field of view in Binoculars?

The term field of view is used to refer to the size of the circular area you are able to see through your binocular. This distance is measured in feet at a distance of 1000 yards. In simple terms, the field of view is how much you are able to see through your binocular.

What is Exit pupil?

The exit pupil is the amount of light that is visible through your binocular’s eye piece. This amount is measured by dividing a binocular’s objective lens with the magnification. Therefore, if a binocular has a magnification of 8X and an objective lens of 42 mm its exit pupil is 5.25. The wider the exit pupil, the brighter the image appears.

What is Eye relief?

Eye relief is the distance between a binocular’s eye piece and your eyes. This distance is measured in ft. A long eye relief reduces strain especially for people who wear glasses.

What is Aperture in binoculars?

Aperture refers to the diameter of a binocular’s objective lens. A big aperture translates to higher light transmission and therefore a brighter image.

What is Interpupillary distance?

The interpupillary distance is the distance between your two eyes. Binoculars can be adjusted according to a person’s interpupillary distance. Most binoculars can be adjusted within a range of between 60 mm and 70 mm.

You can Get further information from this post >> What Do The Numbers On Binoculars Mean – Easy Explanation

To know what to look for when buying binoculars it is wise to categorize binoculars.

How To Choose Binoculars For Hunting

If you are in the market for a pair of binoculars to use during hunts, there are number of things you will want to consider, number one being magnification. For hunting, a binocular with a magnification of 7 to 10X will do just fine. Anything beyond 10X will prove difficult to steady while in the field.

how to choose binoculars for hunting

As a hunter, myself, I recommend going for a binocular with an 8X magnification. An 8X magnification is best complemented by a 42 mm objective lens. However, if you hunt at night a binocular with a 50mm objective lens might be a better option. Nevertheless, such a binocular will be bulky and might weigh you down. One of the most important factors you need to consider is the field of view. Of worth noting is that increase in magnification narrows the field of view.

Therefore, for hunting purposes, a lower magnification will be better than a high magnification. Thus, if you want to know how to choose binoculars for hunting, be keen on the following specs.

  • 8X to 10X magnification
  • 42mm to 50 mm objective lens
  • Multi-coated optics
  • Exterior rubber coating
  • 18 mm eye relief
  • Individual eyepiece focus for medium to long range viewing

Well These Awesome 10 tips of choosing hunting binoculars will help you most. Have a look this infographs.


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How To Choose Binoculars For Bird Watching

How to choose binoculars for birding

The primary purpose of buying binoculars for bird watching is to get a closer and detailed look at the birds you are watching. Therefore, a good binocular for bird watching needs to have a good magnification power. Ideally, a maximum magnification of 10X is recommended.

However, it is important to remember that a wide field of view is also important for bird watching. Thus, an objective lens of 50 mm will be ideal. A 10X50 binocular will give you a better image quality and a wide field of view compared to a 10X42 binocular. However, a 10X50 binocular might require a tripod to stabilize.

Regarding the focusing mechanism, as a bird watcher, you will be served better by a binocular with a central focusing knob. Binoculars with two separated adjustments for the two eyepieces are not ideal for birding. To understand how to choose binoculars for bird watching, be keen on the following specs.

  • Field of view of 340 - 360 feet at 1000 yards
  • Central focus mechanism
  • 8X to 10X magnification
  • 42 to 50 mm objective lens
  • Eye relief of 15 to 20 mm

How to Focus Your Birding Binoculars

How To Choose Binoculars For Wildlife Viewing

There is no much difference between binoculars designed for bird watching and those designed for wildlife viewing. However, your preferences and budget will be crucial when learning how to choose binoculars for wildlife viewing. If you are on a strict budget, then a Porro prism binocular will give you excellent value for your money. On the other hand, if money is not a problem, then a pricier phase corrected roof prism binocular will give you quality for your money.

How to choose binoculars for wildlife viewing

It is important to note that roof prism binoculars are long lasting and less susceptible to damage. In regards to magnification, it will depend on the kind of viewing you are engaged in. If you want binoculars for viewing wading birds a 10X magnification is recommended. Contrastingly, if you want binoculars for viewing animals in enclosed environments such as in woodland areas an 8X magnification will be ideal.

To get the best results go for a binocular with either an ED or HD objective lens glass. Also, go for binoculars that have multicoated optics and in the case of roof prisms select binoculars that are phase corrected. In essence, choose binoculars with the following specs

  • Multicoated optics
  • HD or extra-low dispersion objective lens
  • 8X to 10X magnification
  • Field of view of 110 to 130 feet at 1000 yards
  • Aluminum or magnesium alloy body

How To Choose Binoculars For Safari

To enjoy the beauty and marvels of an African safari, it is important that you travel light. That being said, a compact and lightweight binocular will serve you best. To know how to choose binoculars for safari, there are several factors to consider. Ideally, choose a binocular with a 32 mm objective lens and an 8X magnification. Anything below 32 mm and you will struggle to view animals at dawn and dusk.

On the other hand, anything above 42 mm will be too hefty and bulky for you to carry around. Apart from magnification and objective lens, it is also important to consider a binocular’s ruggedness. Going on a safari means high temperatures, rainfall, dust and frequent movements. An excellent safari binocular should be waterproof and be filled with either nitrogen or argon gas to keep the dust at bay.

Basically, mid-level binoculars will do fine on a safari. Thus, there is no need to cough up $1000 on a binocular for a safari. The main specs to look out for are;

  • Rubberized body
  • Argon filled tubes
  • Coated lenses
  • 8X magnification
  • 42mm objective lens
  • HD optics

How To Choose Binoculars For Hiking

When you are shopping for a binocular for hiking size and weight will be your primary concern. After all, you do not want a binocular weighing you down. For hiking, I recommend going for a compact binocular with either a 20 mm or a 32 mm objective lens. As for the magnification, settle on an 8X magnification. This gives you a good balance between magnification and wide field of view.

Overall, go for a roof prism binocular or a reverse Porro prism model. Roof prism binoculars are more compact compared to Porro prism binoculars. The housing of the binocular should be robust. Thus, a good hiking binocular ought to have a rubberized exterior. These are the main things to note when you want to know how to choose binoculars for hiking. The main specs to look out for in a binocular for hiking are.

  • 25 mm objective lens
  • 8X magnification
  • Polycarbonate rubberized exterior
  • Fully multi-coated lenses
  • Lightweight construction

How To Choose Astronomy Binoculars

While some may opt for a telescope for stargazing and astronomy, there are many reasons why a binocular is better. For starters, binoculars are easier to hold than telescopes. There is a variety of astronomy binoculars you can choose from. When you are wondering how to choose astronomical binoculars, there are several things you will have to consider.

Number one is the magnification and objective lens. If you want a detailed view of the sky, a large binocular with a magnification of between 15X and 30X will be ideal. This magnification should be matched by an objective lens of 50 mm to 70mm. Since you will be using your binoculars at night, the large objective lens will give you a brighter view. The design of astronomy binoculars is also different. Due to their large size, it is recommended to use astronomy binoculars with a tripod.

To make viewing easy, go for a binocular whose eye piece are at an angle of either 45 or 90 degrees. Also, a good astronomy binocular should have prisms crafted from Bak4 glass. There is no need for an astronomy binocular to be waterproofed. Furthermore, the field of view is not as important to astronomers as it is to hunters. The best astronomy binoculars will have the following specs

  • Bak4 glass prisms
  • 70 mm objective lens
  • 20X magnification
  • Tripod adaptable
  • 15 mm or more eye relief
  • Fully multicoated optics

How To Choose Binoculars For Stargazing

There is a lot you can do with a pair of binoculars on a starry night. However, you have to learn first how to choose astronomy binoculars for stargazing. The first factor to consider will be the magnification. Ideally, a 7X or a 10X magnification will give you a clear view of the sky. This magnification should be complemented by a 50 mm objective lens. Therefore, a 7X50mm Binocular or a 10X50 mm will be ideal.

However, it is important to note that the latter binocular will be more difficult to steady than the former. Nevertheless, you can get binocular with an in-built image stabilizer. This feature helps a binocular be stable when in use. Canon is a company synonymous with making high-quality image stabilizer binoculars. Thus, I recommend going for a Canon model. Essentially, the binocular you choose for stargazing should have the following specs.

  • 10X magnification
  • 50 mm objective lens
  • Built-in image stabilizer
  • Fully multicoated optics
  • Central focus mechanism

How To Choose Binoculars For Sports

Sometimes when you are in a crowded stadium getting a clear view of the sporting activity can be difficult. This is where a pair of binocular comes in handy. For sports, a compact and lightweight binocular is recommended. Personally, I recommend a binocular with a magnification of 6X and an objective lens of not more than 32 mm. This configuration offers the best balance between magnification and field of view. Another important feature to consider will be a binocular’s close focus range. This is because in some sports you might want to get a detailed view from a short distance.

A wide field of view preferably of 315 ft at 1000 yards will do great. As for the type of binocular, I tend to go with roof prism binoculars for sporting events. In summary, a binocular for sports ought to have the following specs

  • 6X to 7X magnification
  • 32 mm objective lens
  • 315 ft or more field of view
  • Rubberized exterior
  • Close focus range

How To Choose Military Binoculars

Arguably the most sought after binoculars are military grade binoculars. These are binoculars designed to be used on the battlefields. Though they are used primarily by armed forces, they are also available to civilians. If you want a military binocular, then you have to be prepared to avoid certain specs. Since battlefields are rugged and cruel, military binoculars need to be tough and rugged. Mainly, the best military binoculars are made from aluminum or magnesium alloy. As for the magnification, these binoculars need to be lightweight thus an 8X magnification will do fine. This magnification is complemented by a 42 mm objective lens.

how to choose military binoculars

There is no reason to have fancy specs such as a digital camera or a zoom feature on these binoculars. Therefore, keep away from binoculars with such fancy features. Instead, seek binoculars with either a built-in compass or rangefinder. Military binoculars also come with a head mounting for easy mounting onto a soldier’s helmet. In essence, to learn how to choose military binoculars to consider the following specs.

  • 8X magnification
  • Inbuilt rangefinder
  • 42 mm objective lens
  • Central focus mechanism
  • Waterproof and fog proof body

How To Buy Marine Binoculars

If you are wondering how to choose a good pair of binoculars for boating or fishing, then this section is for you. The best marine binocular is one with a 7X magnification and a 50 mm objective lens. The 7x magnification is ideal because of the unstable nature of boats. Anything above 7X will be unsteady to hold. Complement this magnification with a 50 mm objective lens, and you get a generous field of view and resolution.

But you can choose 8,10,12 even 16 magnification if the binoculars have image stabilization feature. Also keep in mind that the more magnification the weight of the binocualrs will increase. I will advise either you get a pair of binoculars 7x if it doesn't have IS (image stablization) and choose 10 or 12 If it have IS feature.

how to buy marine binoculars

The prisms of the best marine binoculars are crafted from Bak4 glass and not Bak7 glass. Needless to say a marine binocular need to be waterproof as you will be coming into contact with water. To improve your views while fishing or boating buy binoculars with fully multicoated optics or lenses. A long eye relief of about 25 mm is recommended for marine binoculars.

As for the exit pupil, an exit pupil of 7.1 mm will be sufficient for all your fishing and boating needs. Unlike for other binoculars, marine binoculars need to have individual eyepiece focus mechanism as opposed to a central focus. Most marine binoculars are Porro prism binoculars. Bottom line, marine binoculars should have the following specifications

  • 7X magnification (if it doesn't have IS feature)
  • More than 7X magnify if it have IS feature
  • 50 mm objective lens
  • Must be waterproof and filled with nitrogen
  • Bak4 prism glass
  • Individual focus mechanism
  • 25 mm eye relief
  • 7.1 ft exit pupil
  • Fully multicoated optics
  • Built in rangefinder will be a good option


In summary, different binoculars are designed for various applications. Therefore, you have to get a binocular that meets your needs. Needless to say, to get value for your money you will need to know how to choose best binoculars or simply how to choose a good pair of binoculars.


"Smith is an outdoor enthusiast and Just loves everything about binoculars. Since his childhood he has been a fan of optical gadgets & going into the Jungle with his uncle was his favorite pastime. Besides, He loves watching & studying birds & animals. He is a mechanical engineering graduate and New Jersey Resident. He loves to review binoculars and related optical Instruments and loves testing each one of them." When he is not fiddling with one of his binoculars, you can find him playing his favorite sport Pickleball."

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  • Nardia says:

    Hi May I please ask what is a BAK-S1 Prism system?

    It has been advertised for a monocular. Product description says it is the Prism Type but I can’t find anything about it (besides it being in the ads for this product).

    Apologies in advance for my questions but I don’t know who to ask and was hoping you could possibly please shed some light.

    • Binoculars Guru says:

      Thanks for your valuable comment. I think you are talking about this..”4K 10-300X40mm super telephoto zoom monocular telescope(Released in July 2020)” I guess this is just their way of naming things. Let me get some more information and get back.

  • Debbie says:

    Hello…..is there any new information regarding the BAK-S1 Prism system? I was wondering the same thing Nardia was.

    Thank you!

  • John says:

    I saw ads with BAK-S1 prisms associated with the name StarScope. I bought a 40×60 StarScope that turned out to be decent 8×30 monocular.. They sent me their company policy to have no responsibility for errors in specifications.

    They changed their ads following my complaint,. to a still false 10×50. An eyepiece image at 1000 yards pictures a horned animal that had to have been 250 feet tall to fill the frame like that. The little birdy at 800 yards had to be about 180 feet tall. Further, a video showed a zooming image and the word zoom was in the text of this fixed focal length scope.

    The new ad says their zoom scope is 12cm long and includes a photo of it in which the tube diameter is 1/4 the length… or 30mm. There.s no way to squeeze a 40mm objective lens into a 30mm o.d. tube.

    They claim it to be 10-300×40, which I would read as 10x to 300x magnification. Elsewhere they say the zoom range is 300x, but 10x to 300x is a zoom range of only 30x. Things don’t add up.

    If I were to buy one,, I’d expect to receive a decent little scope with a 25mm objective and significantly less that 300x max zoom and less than 10x at the minimum.

  • Anne says:

    Hi! Thanks for all the great, helpful info. I’ve been looking for a pair of binoculars for a while and just when I think I have it narrowed down, I start to question my decision. Here’s what I’m primarily looking for: watching sea life in the Puget Sound from the land. My daughter has a house a block from the water and walks to the water all the time during the day, sunrise, sunset, daytime…. We’ve been there to see orcas and dolphins and awesome binoculars would’ve made it so much better. So how do we get up close and personal in this scenario? We aren’t on a moving boat and most times we aren’t out in the pouring rain. We want great magnification and could use a tripod if that would help. Any suggestions? Also, is there a good recommendation for a place to purchase used quality binoculars? I’m guessing people might upgrade along the way and want to sell a previous pair in great shape. I don’t always trust stuff that’s sold on eBay. Advice would be greatly appreciated as this is all new to me 🙂

  • Peter says:

    What about buying binoculars for the opera.

    The stage will have good lighting.

    You want to see a close up of the singers face.

    They should be light in weight and small in size.

    • Smith says:

      This Can be a good choice. Check Kingscope 3X25 Vintage Opera Glasses Binoculars for Theater Musical Concert- https://amzn.to/3RxmLcy.
      If You have a slightly good budget you can go for Pentax Papilio II 6.5×21 Binoculars also, you won’t be disappointed-https://amzn.to/3C32C8p
      Thanks for being here.

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